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HTTP Request Smuggling

web HIGH

HTTP request smuggling exploits inconsistencies in how front-end and back-end servers parse HTTP message boundaries.

How It Works

HTTP request smuggling exploits inconsistencies in how front-end and back-end servers parse HTTP message boundaries. When a reverse proxy or load balancer forwards requests to a back-end server, both must agree on where one request ends and the next begins. This boundary is defined by either Content-Length (specifying exact body bytes) or Transfer-Encoding: chunked (indicating variable-length chunks). When servers interpret these headers differently, an attacker can craft a malicious request that appears as one request to the front-end but becomes two requests to the back-end.

The classic CL.TE variant works when the front-end prioritizes Content-Length while the back-end honors Transfer-Encoding. An attacker sends a request with both headers where the Content-Length value is smaller than the actual body. The front-end forwards the entire request, believing it ends earlier than it actually does. The back-end processes the declared content length as one request, then interprets the remaining bytes as the start of a new request—which gets prepended to the next legitimate user's request that arrives.

The TE.CL variant reverses this: the front-end reads chunked encoding while the back-end uses Content-Length. TE.TE attacks exploit even subtler differences—both servers support chunked encoding, but one can be tricked through obfuscation like extra spaces, mixed-case headers, or duplicate Transfer-Encoding directives. The attacker's smuggled request fragment poisons the request stream, affecting whatever user request follows.

Impact

  • Authentication bypass — smuggled requests inherit the authenticated session of the subsequent victim request
  • Request hijacking — capture sensitive data (credentials, tokens, API keys) from other users' requests by smuggling a prefix that logs or reflects their data
  • Web cache poisoning — inject malicious content that gets cached and served to all users accessing that resource
  • Cross-site scripting — smuggle requests that inject JavaScript payloads into responses served to other users
  • Access control circumvention — route requests to restricted endpoints by bypassing front-end security filters

Real-World Examples

Security researchers discovered request smuggling vulnerabilities in major CDN providers and reverse proxies throughout 2019-2020, affecting services that process billions of requests daily. Attackers successfully bypassed WAF protections by smuggling malicious payloads that the security layer never inspected, since the WAF and back-end disagreed on request boundaries.

E-commerce platforms running vulnerable configurations experienced account takeover attacks where smuggled requests captured session tokens from subsequent legitimate user requests, granting attackers full account access without credential theft.

Content delivery networks suffered cache poisoning incidents where attackers smuggled requests causing the CDN to cache malicious JavaScript, which was then served to thousands of users requesting the same resource.

Mitigation

  • Deploy HTTP/2 end-to-end — eliminates ambiguity since HTTP/2 uses binary framing with explicit length prefixes
  • Reject ambiguous requests — drop any request containing both Content-Length and Transfer-Encoding headers
  • Normalize forwarded requests — ensure the front-end rewrites requests to use only one length mechanism before forwarding
  • Disable back-end connection reuse — configure each back-end request to use a fresh connection (reduces performance but prevents smuggling)
  • Use identical HTTP parsing — deploy the same server software for both front-end and back-end tiers

Recent CVEs (299)

EPSS 1% CVSS 9.8
CRITICAL PATCH Act Now

An issue was discovered in MediaWiki before 1.35.10, 1.36.x through 1.38.x before 1.38.6, and 1.39.x before 1.39.3. Rated critical severity (CVSS 9.8), this vulnerability is remotely exploitable, no authentication required, low attack complexity. No vendor patch available.

Information Disclosure Request Smuggling Mediawiki +1
NVD
EPSS 2% CVSS 7.5
HIGH PATCH This Week

HTTP Response Smuggling vulnerability in Apache HTTP Server via mod_proxy_uwsgi.4.30 through 2.4.55. Rated high severity (CVSS 7.5), this vulnerability is remotely exploitable, no authentication required, low attack complexity. No vendor patch available.

Apache Information Disclosure Request Smuggling +3
NVD
EPSS 84% CVSS 9.8
CRITICAL Act Now

Some mod_proxy configurations on Apache HTTP Server versions 2.4.0 through 2.4.55 allow a HTTP Request Smuggling attack. Rated critical severity (CVSS 9.8), this vulnerability is remotely exploitable, no authentication required, low attack complexity. No vendor patch available.

Apache Request Smuggling Authentication Bypass +1
NVD
EPSS 5% CVSS 9.1
CRITICAL Act Now

HAProxy before 2.7.3 may allow a bypass of access control because HTTP/1 headers are inadvertently lost in some situations, aka "request smuggling." The HTTP header parsers in HAProxy may accept. Rated critical severity (CVSS 9.1), this vulnerability is remotely exploitable, no authentication required, low attack complexity. No vendor patch available.

Request Smuggling Authentication Bypass Haproxy +1
NVD
EPSS 0% CVSS 8.8
HIGH This Week

Dell EMC PV ME5, versions ME5.1.0.0.0 and ME5.1.0.1.0, contains a Client-side desync Vulnerability. Rated high severity (CVSS 8.8), this vulnerability is remotely exploitable, no authentication required, low attack complexity. No vendor patch available.

XSS Request Smuggling Dell +3
NVD
EPSS 3% CVSS 6.5
MEDIUM POC This Month

The llhttp parser in the http module in Node v18.7.0 does not correctly handle header fields that are not terminated with CLRF. Rated medium severity (CVSS 6.5), this vulnerability is remotely exploitable, no authentication required, low attack complexity. Public exploit code available and no vendor patch available.

Information Disclosure Request Smuggling Node Js +3
NVD
EPSS 1% CVSS 7.5
HIGH This Week

An issue was discovered in Varnish Cache 7.x before 7.1.2 and 7.2.x before 7.2.1. Rated high severity (CVSS 7.5), this vulnerability is remotely exploitable, no authentication required, low attack complexity. No vendor patch available.

Information Disclosure Request Smuggling Varnish Cache +1
NVD
EPSS 1% CVSS 7.5
HIGH PATCH This Week

If Apache Tomcat 8.5.0 to 8.5.82, 9.0.0-M1 to 9.0.67, 10.0.0-M1 to 10.0.26 or 10.1.0-M1 to 10.1.0 was configured to ignore invalid HTTP headers via setting rejectIllegalHeader to false (the default. Rated high severity (CVSS 7.5), this vulnerability is remotely exploitable, no authentication required, low attack complexity. No vendor patch available.

Apache Tomcat Request Smuggling +1
NVD
EPSS 1% CVSS 7.5
HIGH POC PATCH This Week

Requests forwarded by ReverseProxy include the raw query parameters from the inbound request, including unparsable parameters rejected by net/http. Rated high severity (CVSS 7.5), this vulnerability is remotely exploitable, no authentication required, low attack complexity. Public exploit code available.

Information Disclosure Request Smuggling Go
NVD
EPSS 45% CVSS 5.4
MEDIUM This Month

Pulse Secure version 9.115 and below may be susceptible to client-side http request smuggling, When the application receives a POST request, it ignores the request's Content-Length header and leaves. Rated medium severity (CVSS 5.4), this vulnerability is remotely exploitable, low attack complexity. No vendor patch available.

Ivanti Request Smuggling XSS +2
NVD
EPSS 1% CVSS 9.8
CRITICAL POC PATCH Act Now

It was found that Quarkus 2.10.x does not terminate HTTP requests header context which may lead to unpredictable behavior. Rated critical severity (CVSS 9.8), this vulnerability is remotely exploitable, no authentication required, low attack complexity. Public exploit code available and no vendor patch available.

Information Disclosure Request Smuggling Quarkus
NVD GitHub
EPSS 1% CVSS 7.5
HIGH POC This Week

dproxy-nexgen (aka dproxy nexgen) re-uses the DNS transaction id (TXID) value from client queries, which allows attackers (able to send queries to the resolver) to conduct DNS cache-poisoning attacks. Rated high severity (CVSS 7.5), this vulnerability is remotely exploitable, no authentication required, low attack complexity. Public exploit code available and no vendor patch available.

Information Disclosure Request Smuggling Dproxy Nexgen
NVD
EPSS 1% CVSS 6.5
MEDIUM POC PATCH This Month

Acceptance of some invalid Transfer-Encoding headers in the HTTP/1 client in net/http before Go 1.17.12 and Go 1.18.4 allows HTTP request smuggling if combined with an intermediate server that also. Rated medium severity (CVSS 6.5), this vulnerability is remotely exploitable, no authentication required, low attack complexity. Public exploit code available.

Information Disclosure Request Smuggling Go
NVD
EPSS 1% CVSS 6.1
MEDIUM This Month

A vulnerability in the VPN web client services component of Cisco Adaptive Security Appliance (ASA) Software and Cisco Firepower Threat Defense (FTD) Software could allow an unauthenticated, remote. Rated medium severity (CVSS 6.1), this vulnerability is remotely exploitable, no authentication required, low attack complexity. No vendor patch available.

Request Smuggling Cisco XSS +2
NVD VulDB
EPSS 2% CVSS 7.5
HIGH This Week

Improper Input Validation vulnerability in HTTP/2 request validation of Apache Traffic Server allows an attacker to create smuggle or cache poison attacks.0.0 to 9.1.2. Rated high severity (CVSS 7.5), this vulnerability is remotely exploitable, no authentication required, low attack complexity. No vendor patch available.

Apache Information Disclosure Request Smuggling +3
NVD
EPSS 69% CVSS 6.5
MEDIUM POC PATCH THREAT This Month

The llhttp parser <v14.20.1, <v16.17.1 and <v18.9.1 in the http module in Node.js does not correctly handle multi-line Transfer-Encoding headers. Rated medium severity (CVSS 6.5), this vulnerability is remotely exploitable, no authentication required, low attack complexity. Public exploit code available.

Information Disclosure Node.js Request Smuggling +6
NVD
EPSS 81% CVSS 6.5
MEDIUM POC PATCH THREAT This Month

The llhttp parser <v14.20.1, <v16.17.1 and <v18.9.1 in the http module in Node.js does not strictly use the CRLF sequence to delimit HTTP requests. Rated medium severity (CVSS 6.5), this vulnerability is remotely exploitable, no authentication required, low attack complexity. Public exploit code available.

Information Disclosure Node.js Request Smuggling +4
NVD
EPSS 42% CVSS 6.5
MEDIUM POC PATCH THREAT This Month

The llhttp parser <v14.20.1, <v16.17.1 and <v18.9.1 in the http module in Node.js does not correctly parse and validate Transfer-Encoding headers and can lead to HTTP Request Smuggling (HRS). Rated medium severity (CVSS 6.5), this vulnerability is remotely exploitable, no authentication required, low attack complexity. Public exploit code available.

Information Disclosure Node.js Request Smuggling +6
NVD
EPSS 2% CVSS 6.5
MEDIUM POC PATCH This Month

HTTP::Daemon is a simple http server class written in perl. Rated medium severity (CVSS 6.5), this vulnerability is remotely exploitable, no authentication required, low attack complexity. Public exploit code available.

Information Disclosure Apache Nginx +2
NVD GitHub
EPSS 19% CVSS 7.5
HIGH This Week

Inconsistent Interpretation of HTTP Requests ('HTTP Request Smuggling') vulnerability in mod_proxy_ajp of Apache HTTP Server allows an attacker to smuggle requests to the AJP server it forwards. Rated high severity (CVSS 7.5), this vulnerability is remotely exploitable, no authentication required, low attack complexity. No vendor patch available.

Information Disclosure Apache Request Smuggling +3
NVD
EPSS 8% CVSS 9.8
CRITICAL PATCH Act Now

Improper parsing of HTTP requests in Pallets Werkzeug v2.1.0 and below allows attackers to perform HTTP Request Smuggling using a crafted HTTP request with multiple requests included inside the body. Rated critical severity (CVSS 9.8), this vulnerability is remotely exploitable, no authentication required, low attack complexity. This HTTP Request/Response Smuggling vulnerability could allow attackers to manipulate HTTP request interpretation between frontend and backend servers.

Information Disclosure Request Smuggling Werkzeug
NVD GitHub
EPSS 1% CVSS 5.9
MEDIUM PATCH This Month

A flaw was found in the original fix for the netty-codec-http CVE-2021-21409, where the OpenShift Logging openshift-logging/elasticsearch6-rhel8 container was incomplete. Rated medium severity (CVSS 5.9), this vulnerability is remotely exploitable, no authentication required. This HTTP Request/Response Smuggling vulnerability could allow attackers to manipulate HTTP request interpretation between frontend and backend servers.

Information Disclosure Request Smuggling Origin Aggregated Logging
NVD GitHub
EPSS 3% CVSS 8.1
HIGH PATCH This Week

Twisted is an event-based framework for internet applications, supporting Python 3.6+. Rated high severity (CVSS 8.1), this vulnerability is remotely exploitable, no authentication required. This HTTP Request/Response Smuggling vulnerability could allow attackers to manipulate HTTP request interpretation between frontend and backend servers.

Information Disclosure Python Request Smuggling +4
NVD GitHub
EPSS 2% CVSS 7.5
HIGH PATCH This Week

Puma is a simple, fast, multi-threaded, parallel HTTP 1.1 server for Ruby/Rack applications. Rated high severity (CVSS 7.5), this vulnerability is remotely exploitable, no authentication required, low attack complexity. This HTTP Request/Response Smuggling vulnerability could allow attackers to manipulate HTTP request interpretation between frontend and backend servers.

Information Disclosure Request Smuggling Puma +2
NVD GitHub
EPSS 2% CVSS 9.8
CRITICAL PATCH Act Now

mitmproxy is an interactive, SSL/TLS-capable intercepting proxy. Rated critical severity (CVSS 9.8), this vulnerability is remotely exploitable, no authentication required, low attack complexity. This HTTP Request/Response Smuggling vulnerability could allow attackers to manipulate HTTP request interpretation between frontend and backend servers.

Information Disclosure Request Smuggling Mitmproxy
NVD GitHub
EPSS 2% CVSS 7.5
HIGH PATCH This Week

Waitress is a Web Server Gateway Interface server for Python 2 and 3. Rated high severity (CVSS 7.5), this vulnerability is remotely exploitable, no authentication required, low attack complexity. This HTTP Request/Response Smuggling vulnerability could allow attackers to manipulate HTTP request interpretation between frontend and backend servers.

Information Disclosure Python Request Smuggling +2
NVD GitHub
EPSS 28% CVSS 9.8
CRITICAL PATCH Act Now

Apache HTTP Server 2.4.52 and earlier fails to close inbound connection when errors are encountered discarding the request body, exposing the server to HTTP Request Smuggling. Rated critical severity (CVSS 9.8), this vulnerability is remotely exploitable, no authentication required, low attack complexity. This HTTP Request/Response Smuggling vulnerability could allow attackers to manipulate HTTP request interpretation between frontend and backend servers.

Information Disclosure Apache Request Smuggling +7
NVD
EPSS 5% CVSS 7.5
HIGH This Week

An HTTP smuggling attack in the web application of D-Link DIR-X1860 before v1.10WWB09_Beta allows a remote unauthenticated attacker to DoS the web application via sending a specific HTTP packet. Rated high severity (CVSS 7.5), this vulnerability is remotely exploitable, no authentication required, low attack complexity. No vendor patch available.

Information Disclosure Request Smuggling D-Link +1
NVD VulDB
EPSS 3% CVSS 7.5
HIGH This Week

A misconfiguration in HTTP/1.0 and HTTP/1.1 of the web interface in TP-Link AX10v1 before V1_211117 allows a remote unauthenticated attacker to send a specially crafted HTTP request and receive a. Rated high severity (CVSS 7.5), this vulnerability is remotely exploitable, no authentication required, low attack complexity. No vendor patch available.

TP-Link Request Smuggling Information Disclosure +1
NVD VulDB
EPSS 3% CVSS 6.5
MEDIUM PATCH This Month

Netty is an asynchronous event-driven network application framework for rapid development of maintainable high performance protocol servers & clients. Rated medium severity (CVSS 6.5), this vulnerability is remotely exploitable, no authentication required, low attack complexity. This HTTP Request/Response Smuggling vulnerability could allow attackers to manipulate HTTP request interpretation between frontend and backend servers.

Request Smuggling Information Disclosure Netty +17
NVD GitHub
EPSS 2% CVSS 7.5
HIGH This Week

An HTTP request smuggling attack in TP-Link AX10v1 before v1_211117 allows a remote unauthenticated attacker to DoS the web application via sending a specific HTTP packet. Rated high severity (CVSS 7.5), this vulnerability is remotely exploitable, no authentication required, low attack complexity. No vendor patch available.

Information Disclosure Request Smuggling TP-Link +1
NVD VulDB
EPSS 3% CVSS 7.5
HIGH POC This Week

M-Files Web before 20.10.9524.1 allows a denial of service via overlapping ranges (in HTTP requests with crafted Range or Request-Range headers). Rated high severity (CVSS 7.5), this vulnerability is remotely exploitable, no authentication required, low attack complexity. Public exploit code available and no vendor patch available.

Request Smuggling Denial Of Service M Files Web
NVD
EPSS 1% CVSS 6.5
MEDIUM PATCH This Month

Symfony/Http-Kernel is the HTTP kernel component for Symfony, a PHP framework for web and console applications and a set of reusable PHP components. Rated medium severity (CVSS 6.5), this vulnerability is remotely exploitable, no authentication required, low attack complexity. This HTTP Request/Response Smuggling vulnerability could allow attackers to manipulate HTTP request interpretation between frontend and backend servers.

Request Smuggling PHP Information Disclosure +1
NVD GitHub
EPSS 5% CVSS 7.5
HIGH This Week

An HTTP request smuggling in web application in ASUS ROG Rapture GT-AX11000, RT-AX3000, RT-AX55, RT-AX56U, RT-AX56U_V2, RT-AX58U, RT-AX82U, RT-AX82U GUNDAM EDITION, RT-AX86 Series(RT-AX86U/RT-AX86S),. Rated high severity (CVSS 7.5), this vulnerability is remotely exploitable, no authentication required, low attack complexity. No vendor patch available.

Request Smuggling Information Disclosure Gt Ax11000 Firmware +17
NVD VulDB
EPSS 1% CVSS 7.5
HIGH PATCH This Week

A vulnerability has been detected in HyperLedger Fabric v1.4.0, v2.0.0, v2.0.1, v2.3.0. Rated high severity (CVSS 7.5), this vulnerability is remotely exploitable, no authentication required, low attack complexity. This HTTP Request/Response Smuggling vulnerability could allow attackers to manipulate HTTP request interpretation between frontend and backend servers.

Request Smuggling Information Disclosure Fabric
NVD GitHub
EPSS 3% CVSS 6.5
MEDIUM POC PATCH This Month

The parser in accepts requests with a space (SP) right after the header name before the colon. Rated medium severity (CVSS 6.5), this vulnerability is remotely exploitable, no authentication required, low attack complexity. Public exploit code available.

Request Smuggling Information Disclosure Llhttp +2
NVD
EPSS 1% CVSS 7.5
HIGH PATCH This Week

Belledonne Belle-sip before 5.0.20 can crash applications such as Linphone via an invalid From header (request URI without a parameter) in an unauthenticated SIP message, a different issue than. Rated high severity (CVSS 7.5), this vulnerability is remotely exploitable, no authentication required, low attack complexity. This HTTP Request/Response Smuggling vulnerability could allow attackers to manipulate HTTP request interpretation between frontend and backend servers.

Request Smuggling Denial Of Service Belle Sip
NVD GitHub
EPSS 2% CVSS 6.5
MEDIUM POC PATCH This Month

The parse function in llhttp < 2.1.4 and < 6.0.6. Rated medium severity (CVSS 6.5), this vulnerability is remotely exploitable, no authentication required, low attack complexity. Public exploit code available.

Request Smuggling Information Disclosure Llhttp +2
NVD
EPSS 1% CVSS 8.1
HIGH This Week

Firefox incorrectly accepted a newline in a HTTP/3 header, interpretting it as two separate headers. Rated high severity (CVSS 8.1), this vulnerability is remotely exploitable, no authentication required, low attack complexity. No vendor patch available.

Mozilla Request Smuggling Information Disclosure +2
NVD
EPSS 1% CVSS 3.7
LOW PATCH Monitor

Puma is a HTTP 1.1 server for Ruby/Rack applications. Rated low severity (CVSS 3.7), this vulnerability is remotely exploitable. This HTTP Request/Response Smuggling vulnerability could allow attackers to manipulate HTTP request interpretation between frontend and backend servers.

Request Smuggling Apache Information Disclosure +2
NVD GitHub
EPSS 1% CVSS 7.5
HIGH POC This Week

An issue was discovered in zeek version 4.1.0. Rated high severity (CVSS 7.5), this vulnerability is remotely exploitable, no authentication required, low attack complexity. Public exploit code available and no vendor patch available.

Request Smuggling Information Disclosure Zeek
NVD GitHub
EPSS 1% CVSS 5.3
MEDIUM This Month

Ping Identity PingAccess before 5.3.3 allows HTTP request smuggling via header manipulation. Rated medium severity (CVSS 5.3), this vulnerability is remotely exploitable, no authentication required, low attack complexity. No vendor patch available.

Request Smuggling Information Disclosure Pingaccess
NVD
EPSS 1% CVSS 9.8
CRITICAL PATCH Act Now

mitmproxy is an interactive, SSL/TLS-capable intercepting proxy. Rated critical severity (CVSS 9.8), this vulnerability is remotely exploitable, no authentication required, low attack complexity. No vendor patch available.

Request Smuggling Information Disclosure Mitmproxy
NVD GitHub
EPSS 3% CVSS 9.4
CRITICAL POC Act Now

SAP Web Dispatcher versions - 7.49, 7.53, 7.77, 7.81, KRNL64NUC - 7.22, 7.22EXT, 7.49, KRNL64UC -7.22, 7.22EXT, 7.49, 7.53, KERNEL - 7.22, 7.49, 7.53, 7.77, 7.81, 7.83 processes allow an. Rated critical severity (CVSS 9.4), this vulnerability is remotely exploitable, no authentication required, low attack complexity. Public exploit code available and no vendor patch available.

Information Disclosure Request Smuggling SAP +1
NVD
EPSS 1% CVSS 5.3
MEDIUM This Month

In PEPPERL+FUCHS WirelessHART-Gateway <= 3.0.8 a vulnerability may allow remote attackers to rewrite links and URLs in cached pages to arbitrary strings. Rated medium severity (CVSS 5.3), this vulnerability is remotely exploitable, no authentication required, low attack complexity. No vendor patch available.

Request Smuggling Information Disclosure Wha Gw F2D2 0 As Z2 Eth Firmware +1
NVD
EPSS 1% CVSS 7.5
HIGH PATCH This Week

Belledonne Belle-sip before 4.5.20, as used in Linphone and other products, can crash via an invalid From header in a SIP message. Rated high severity (CVSS 7.5), this vulnerability is remotely exploitable, no authentication required, low attack complexity. This HTTP Request/Response Smuggling vulnerability could allow attackers to manipulate HTTP request interpretation between frontend and backend servers.

Request Smuggling Denial Of Service Belle Sip
NVD GitHub
EPSS 2% CVSS 7.5
HIGH POC PATCH This Week

An issue was discovered in the actix-http crate before 3.0.0-beta.9 for Rust. Rated high severity (CVSS 7.5), this vulnerability is remotely exploitable, no authentication required, low attack complexity. Public exploit code available and no vendor patch available.

Request Smuggling Information Disclosure Actix Http +1
NVD
EPSS 1% CVSS 4.3
MEDIUM This Month

An improper neutralization of CRLF sequences in HTTP headers ('HTTP Response Splitting') vulnerability In FortiManager and FortiAnalyzer GUI 7.0.0, 6.4.6 and below, 6.2.8 and below, 6.0.11 and below,. Rated medium severity (CVSS 4.3), this vulnerability is remotely exploitable, low attack complexity. No vendor patch available.

Request Smuggling Information Disclosure Fortianalyzer +1
NVD
EPSS 2% CVSS 6.5
MEDIUM PATCH This Month

Varnish Cache, with HTTP/2 enabled, allows request smuggling and VCL authorization bypass via a large Content-Length header for a POST request. Rated medium severity (CVSS 6.5), this vulnerability is remotely exploitable, no authentication required, low attack complexity. This HTTP Request/Response Smuggling vulnerability could allow attackers to manipulate HTTP request interpretation between frontend and backend servers.

Request Smuggling Authentication Bypass Varnish Cache +2
NVD GitHub
EPSS 1% CVSS 4.3
MEDIUM This Month

SAP Web Dispatcher and Internet Communication Manager (ICM), versions - KRNL32NUC 7.21, 7.21EXT, 7.22, 7.22EXT, KRNL32UC 7.21, 7.21EXT, 7.22, 7.22EXT, KRNL64NUC 7.21, 7.21EXT, 7.22, 7.22EXT, 7.49,. Rated medium severity (CVSS 4.3), this vulnerability is remotely exploitable, low attack complexity. No vendor patch available.

Information Disclosure Request Smuggling SAP +2
NVD
EPSS 75% CVSS 5.3
MEDIUM PATCH This Month

Apache Tomcat 10.0.0-M1 to 10.0.6, 9.0.0.M1 to 9.0.46 and 8.5.0 to 8.5.66 did not correctly parse the HTTP transfer-encoding request header in some circumstances leading to the possibility to request. Rated medium severity (CVSS 5.3), this vulnerability is remotely exploitable, no authentication required, low attack complexity. This HTTP Request/Response Smuggling vulnerability could allow attackers to manipulate HTTP request interpretation between frontend and backend servers.

Tomcat Request Smuggling Apache +22
NVD VulDB
EPSS 1% CVSS 5.3
MEDIUM POC PATCH This Month

hyper is an HTTP library for rust. Rated medium severity (CVSS 5.3), this vulnerability is remotely exploitable, no authentication required, low attack complexity. Public exploit code available.

Request Smuggling Information Disclosure Hyper
NVD GitHub
EPSS 2% CVSS 7.5
HIGH This Week

Invalid values in the Content-Length header sent to Apache Traffic Server allows an attacker to smuggle requests.0.0 to 7.1.12, 8.0.0 to 8.1.1, 9.0.0 to 9.0.1. Rated high severity (CVSS 7.5), this vulnerability is remotely exploitable, no authentication required, low attack complexity. No vendor patch available.

Request Smuggling Apache Information Disclosure +2
NVD
EPSS 4% CVSS 7.5
HIGH This Week

Incorrect handling of url fragment vulnerability of Apache Traffic Server allows an attacker to poison the cache.0.0 to 7.1.12, 8.0.0 to 8.1.1, 9.0.0 to 9.0.1. Rated high severity (CVSS 7.5), this vulnerability is remotely exploitable, no authentication required, low attack complexity. No vendor patch available.

Request Smuggling Apache Information Disclosure +2
NVD
EPSS 60% CVSS 9.8
CRITICAL PATCH Act Now

Apache Dubbo prior to 2.7.9 support Tag routing which will enable a customer to route the request to the right server. Rated critical severity (CVSS 9.8), this vulnerability is remotely exploitable, no authentication required, low attack complexity. No vendor patch available.

Request Smuggling Apache Information Disclosure +1
NVD
EPSS 1% CVSS 7.5
HIGH POC This Week

An HTTP Request Smuggling vulnerability in Pulse Secure Virtual Traffic Manager before 21.1 could allow an attacker to smuggle an HTTP request through an HTTP/2 Header. Rated high severity (CVSS 7.5), this vulnerability is remotely exploitable, no authentication required, low attack complexity. Public exploit code available and no vendor patch available.

Request Smuggling Information Disclosure Ivanti +1
NVD
EPSS 5% CVSS 5.9
MEDIUM PATCH This Month

Netty is an open-source, asynchronous event-driven network application framework for rapid development of maintainable high performance protocol servers & clients. Rated medium severity (CVSS 5.9), this vulnerability is remotely exploitable, no authentication required. This HTTP Request/Response Smuggling vulnerability could allow attackers to manipulate HTTP request interpretation between frontend and backend servers.

Request Smuggling Information Disclosure Netty +17
NVD GitHub
EPSS 19% CVSS 5.9
MEDIUM PATCH This Month

Netty is an open-source, asynchronous event-driven network application framework for rapid development of maintainable high performance protocol servers & clients. Rated medium severity (CVSS 5.9), this vulnerability is remotely exploitable, no authentication required. This HTTP Request/Response Smuggling vulnerability could allow attackers to manipulate HTTP request interpretation between frontend and backend servers.

Request Smuggling Information Disclosure Netty +7
NVD GitHub
EPSS 1% CVSS 4.8
MEDIUM PATCH This Month

A flaw was found in Undertow. Rated medium severity (CVSS 4.8), this vulnerability is remotely exploitable, no authentication required. No vendor patch available.

Request Smuggling XSS Undertow +2
NVD
EPSS 1% CVSS 6.5
MEDIUM PATCH This Month

This affects all versions before 10.1.14 and from 10.2.0 to 10.2.4 of package com.typesafe.akka:akka-http-core. Rated medium severity (CVSS 6.5), this vulnerability is remotely exploitable, no authentication required, low attack complexity. No vendor patch available.

Request Smuggling Information Disclosure Akka Http
NVD GitHub
EPSS 36% CVSS 5.9
MEDIUM POC PATCH THREAT This Month

The package python/cpython from 0 and before 3.6.13, from 3.7.0 and before 3.7.10, from 3.8.0 and before 3.8.8, from 3.9.0 and before 3.9.2 are vulnerable to Web Cache Poisoning via. Rated medium severity (CVSS 5.9), this vulnerability is remotely exploitable, no authentication required. Public exploit code available.

Request Smuggling Python Information Disclosure +11
NVD GitHub
EPSS 5% CVSS 8.1
HIGH PATCH This Week

hyper is an open-source HTTP library for Rust (crates.io). Rated high severity (CVSS 8.1), this vulnerability is remotely exploitable, no authentication required. This HTTP Request/Response Smuggling vulnerability could allow attackers to manipulate HTTP request interpretation between frontend and backend servers.

Request Smuggling Information Disclosure Hyper
NVD GitHub
EPSS 1% CVSS 7.5
HIGH This Week

Some Huawei products have an inconsistent interpretation of HTTP requests vulnerability. Rated high severity (CVSS 7.5), this vulnerability is remotely exploitable, no authentication required, low attack complexity. No vendor patch available.

Request Smuggling Information Disclosure Huawei +3
NVD
EPSS 1% CVSS 5.3
MEDIUM This Month

In JetBrains Ktor before 1.4.3, HTTP Request Smuggling was possible. Rated medium severity (CVSS 5.3), this vulnerability is remotely exploitable, no authentication required, low attack complexity. No vendor patch available.

Request Smuggling Information Disclosure Ktor
NVD
EPSS 1% CVSS 5.4
MEDIUM This Month

SAP Commerce Cloud, versions - 1808, 1811, 1905, 2005, 2011, allows an authenticated attacker to include invalidated data in the HTTP response Content Type header, due to improper input validation,. Rated medium severity (CVSS 5.4), this vulnerability is remotely exploitable, low attack complexity. No vendor patch available.

Request Smuggling XSS SAP +1
NVD
EPSS 1% CVSS 6.5
MEDIUM PATCH This Month

An issue was discovered in the tiny_http crate through 2020-06-16 for Rust. Rated medium severity (CVSS 6.5), this vulnerability is remotely exploitable, no authentication required, low attack complexity. No vendor patch available.

Request Smuggling Information Disclosure Tiny Http +1
NVD
EPSS 3% CVSS 9.8
CRITICAL PATCH Act Now

An issue was discovered in the hyper crate before 0.12.34 for Rust. Rated critical severity (CVSS 9.8), this vulnerability is remotely exploitable, no authentication required, low attack complexity. This HTTP Request/Response Smuggling vulnerability could allow attackers to manipulate HTTP request interpretation between frontend and backend servers.

RCE Request Smuggling Hyper
NVD
EPSS 1% CVSS 7.5
HIGH PATCH This Week

async-h1 is an asynchronous HTTP/1.1 parser for Rust (crates.io). Rated high severity (CVSS 7.5), this vulnerability is remotely exploitable, no authentication required. No vendor patch available.

Request Smuggling Information Disclosure Async H1
NVD GitHub
EPSS 1% CVSS 5.4
MEDIUM POC This Month

Kamailio before 5.4.0, as used in Sip Express Router (SER) in Sippy Softswitch 4.5 through 5.2 and other products, allows a bypass of a header-removal protection mechanism via whitespace characters. Rated medium severity (CVSS 5.4), this vulnerability is remotely exploitable, low attack complexity. Public exploit code available and no vendor patch available.

Request Smuggling Authentication Bypass Kamailio
NVD
EPSS 1% CVSS 6.5
MEDIUM This Month

In JetBrains Ktor before 1.4.1, HTTP request smuggling was possible. Rated medium severity (CVSS 6.5), this vulnerability is remotely exploitable, no authentication required, low attack complexity. No vendor patch available.

Request Smuggling Information Disclosure Ktor
NVD
EPSS 2% CVSS 7.5
HIGH PATCH This Week

This affects the package find-my-way before 2.2.5, from 3.0.0 and before 3.0.5. Rated high severity (CVSS 7.5), this vulnerability is remotely exploitable, no authentication required, low attack complexity. This HTTP Request/Response Smuggling vulnerability could allow attackers to manipulate HTTP request interpretation between frontend and backend servers.

Request Smuggling Denial Of Service Find My Way
NVD GitHub
EPSS 4% CVSS 7.5
HIGH PATCH This Week

An issue was discovered in Ruby through 2.5.8, 2.6.x through 2.6.6, and 2.7.x through 2.7.1. Rated high severity (CVSS 7.5), this vulnerability is remotely exploitable, no authentication required, low attack complexity. This HTTP Request/Response Smuggling vulnerability could allow attackers to manipulate HTTP request interpretation between frontend and backend servers.

Request Smuggling Authentication Bypass Ruby +2
NVD GitHub
EPSS 1% CVSS 4.8
MEDIUM PATCH This Month

A flaw was discovered in all versions of Undertow before Undertow 2.2.0.Final, where HTTP request smuggling related to CVE-2017-2666 is possible against HTTP/1.x and HTTP/2 due to permitting invalid. Rated medium severity (CVSS 4.8), this vulnerability is remotely exploitable, no authentication required. No vendor patch available.

XSS Request Smuggling Undertow +2
NVD
EPSS 5% CVSS 7.4
HIGH This Week

Node.js < 12.18.4 and < 14.11 can be exploited to perform HTTP desync attacks and deliver malicious payloads to unsuspecting users. Rated high severity (CVSS 7.4), this vulnerability is remotely exploitable, no authentication required. No vendor patch available.

Node.js Request Smuggling Information Disclosure +3
NVD
EPSS 3% CVSS 6.5
MEDIUM This Month

An issue was discovered in Squid before 4.13 and 5.x before 5.0.4. Rated medium severity (CVSS 6.5), this vulnerability is remotely exploitable, low attack complexity. No vendor patch available.

Request Smuggling Authentication Bypass Squid +4
NVD GitHub
EPSS 90% CVSS 7.5
HIGH PATCH This Week

Apache HTTP Server versions 2.4.20 to 2.4.43. Rated high severity (CVSS 7.5), this vulnerability is remotely exploitable, no authentication required, low attack complexity. This HTTP Request/Response Smuggling vulnerability could allow attackers to manipulate HTTP request interpretation between frontend and backend servers.

Apache Request Smuggling Denial Of Service +25
NVD
EPSS 59% CVSS 7.5
HIGH POC PATCH THREAT This Week

Apache HTTP Server versions 2.4.20 to 2.4.43 When trace/debug was enabled for the HTTP/2 module and on certain traffic edge patterns, logging statements were made on the wrong connection, causing. Rated high severity (CVSS 7.5), this vulnerability is remotely exploitable, no authentication required, low attack complexity. Public exploit code available.

Apache Request Smuggling Information Disclosure +13
NVD
EPSS 6% CVSS 8.8
HIGH PATCH This Week

An issue was discovered in http/ContentLengthInterpreter.cc in Squid before 4.12 and 5.x before 5.0.3. Rated high severity (CVSS 8.8), this vulnerability is remotely exploitable, low attack complexity. This HTTP Request/Response Smuggling vulnerability could allow attackers to manipulate HTTP request interpretation between frontend and backend servers.

Request Smuggling Information Disclosure Squid +1
NVD GitHub
EPSS 1% CVSS 7.5
HIGH This Week

goliath through 1.0.6 allows request smuggling attacks where goliath is used as a backend and a frontend proxy also being vulnerable. Rated high severity (CVSS 7.5), this vulnerability is remotely exploitable, no authentication required, low attack complexity. No vendor patch available.

Request Smuggling Information Disclosure Goliath
NVD GitHub
EPSS 1% CVSS 7.5
HIGH This Week

agoo prior to 2.14.0 allows request smuggling attacks where agoo is used as a backend and a frontend proxy also being vulnerable. Rated high severity (CVSS 7.5), this vulnerability is remotely exploitable, no authentication required, low attack complexity. No vendor patch available.

Request Smuggling Information Disclosure Agoo
NVD GitHub
EPSS 1% CVSS 7.5
HIGH This Week

reel through 0.6.1 allows Request Smuggling attacks due to incorrect Content-Length and Transfer encoding header parsing. Rated high severity (CVSS 7.5), this vulnerability is remotely exploitable, no authentication required, low attack complexity. No vendor patch available.

Request Smuggling Information Disclosure Reel
NVD
EPSS 1% CVSS 6.5
MEDIUM PATCH This Month

A flaw was found in Undertow in versions before 2.1.1.Final, regarding the processing of invalid HTTP requests with large chunk sizes. Rated medium severity (CVSS 6.5), this vulnerability is remotely exploitable, no authentication required, low attack complexity. No vendor patch available.

Request Smuggling Information Disclosure Undertow +7
NVD
EPSS 1% CVSS 6.1
MEDIUM PATCH This Month

meinheld prior to 1.0.2 is vulnerable to HTTP Request Smuggling. Rated medium severity (CVSS 6.1), this vulnerability is remotely exploitable, no authentication required, low attack complexity. This HTTP Request/Response Smuggling vulnerability could allow attackers to manipulate HTTP request interpretation between frontend and backend servers.

Request Smuggling Information Disclosure Meinheld
NVD GitHub
EPSS 3% CVSS 7.5
HIGH PATCH This Week

In Puma (RubyGem) before 4.3.5 and 3.12.6, a client could smuggle a request through a proxy, causing the proxy to send a response back to another unknown client. Rated high severity (CVSS 7.5), this vulnerability is remotely exploitable, no authentication required, low attack complexity. No vendor patch available.

Request Smuggling Information Disclosure Puma +3
NVD GitHub
EPSS 4% CVSS 7.5
HIGH PATCH This Week

In Puma (RubyGem) before 4.3.4 and 3.12.5, an attacker could smuggle an HTTP response, by using an invalid transfer-encoding header. Rated high severity (CVSS 7.5), this vulnerability is remotely exploitable, no authentication required, low attack complexity. This HTTP Request/Response Smuggling vulnerability could allow attackers to manipulate HTTP request interpretation between frontend and backend servers.

Request Smuggling Information Disclosure Puma +2
NVD GitHub
EPSS 1% CVSS 6.1
MEDIUM PATCH This Month

netius prior to 1.17.58 is vulnerable to HTTP Request Smuggling. Rated medium severity (CVSS 6.1), this vulnerability is remotely exploitable, no authentication required, low attack complexity. This HTTP Request/Response Smuggling vulnerability could allow attackers to manipulate HTTP request interpretation between frontend and backend servers.

Request Smuggling Information Disclosure Netius
NVD
EPSS 1% CVSS 7.5
HIGH This Week

An issue was discovered in GitLab 10.7.0 and later through 12.9.2. Rated high severity (CVSS 7.5), this vulnerability is remotely exploitable, no authentication required, low attack complexity. No vendor patch available.

Gitlab Request Smuggling Information Disclosure
NVD
EPSS 1% CVSS 7.5
HIGH This Week

An issue was discovered in GitLab Community Edition (CE) and Enterprise Edition (EE) before 12.7.9, 12.8.x before 12.8.9, and 12.9.x before 12.9.3. Rated high severity (CVSS 7.5), this vulnerability is remotely exploitable, no authentication required, low attack complexity. No vendor patch available.

Gitlab Request Smuggling Information Disclosure
NVD
EPSS 3% CVSS 7.5
HIGH PATCH This Week

An issue was discovered in OpenResty before 1.15.8.4. Rated high severity (CVSS 7.5), this vulnerability is remotely exploitable, no authentication required, low attack complexity. This HTTP Request/Response Smuggling vulnerability could allow attackers to manipulate HTTP request interpretation between frontend and backend servers.

Request Smuggling Information Disclosure Openresty +1
NVD GitHub
EPSS 2% CVSS 9.8
CRITICAL POC PATCH Act Now

All versions of io.micronaut:micronaut-http-client before 1.2.11 and all versions from 1.3.0 before 1.3.2 are vulnerable to HTTP Request Header Injection due to not validating request headers passed. Rated critical severity (CVSS 9.8), this vulnerability is remotely exploitable, no authentication required, low attack complexity. Public exploit code available.

Request Smuggling Code Injection Micronaut
NVD GitHub
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Quick Facts

Typical Severity
HIGH
Category
web
Total CVEs
299

Related CWEs

MITRE ATT&CK

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