Skip to main content

Ruby WEBrick CVE-2026-38969

HIGH
HTTP Request/Response Smuggling (CWE-444)
2026-07-02 cve@mitre.org
7.5
CVSS 3.1 · Vendor: mitre
Share

Severity by source

Vendor (mitre) PRIMARY
7.5 HIGH
AV:N/AC:L/PR:N/UI:N/S:U/C:N/I:H/A:N
vuln.today AI
7.5 HIGH

Remote, unauthenticated, low-complexity smuggling with no user interaction; impact is integrity-only (request desync/injection), no direct confidentiality or availability loss, scope unchanged.

3.1 AV:N/AC:L/PR:N/UI:N/S:U/C:N/I:H/A:N
4.0 AV:N/AC:L/AT:N/PR:N/UI:N/VC:N/VI:H/VA:N/SC:N/SI:N/SA:N
SUSE
7.3 HIGH
AV:N/AC:L/PR:N/UI:N/S:U/C:L/I:L/A:L

Primary rating from Vendor (mitre).

CVSS VectorVendor: mitre

Attack Vector
Network
Attack Complexity
Low
Privileges Required
None
User Interaction
None
Scope
Unchanged
Confidentiality
None
Integrity
High
Availability
None

Lifecycle Timeline

3
Analysis Generated
Jul 06, 2026 - 18:31 vuln.today
CVSS changed
Jul 06, 2026 - 16:22 NVD
7.5 (HIGH)
CVE Published
Jul 02, 2026 - 21:16 cve.org
UNKNOWN (no severity yet)

DescriptionCVE.org

ruby webrick through v1.9.2 WEBrick reparses trailer Content-Length into canonical request state, enabling request smuggling.

AnalysisAI

HTTP request smuggling in Ruby's WEBrick HTTP server through v1.9.2 allows remote attackers to desynchronize front-end/back-end request parsing by exploiting how WEBrick reparses a Content-Length value supplied in chunked trailers back into the canonical request state. Any deployment fronting WEBrick with a proxy, load balancer, or CDN that disagrees on message length can have requests smuggled past it, enabling request routing manipulation and information disclosure. Publicly available exploit code exists (SSVC exploitation status: poc), though EPSS remains low at 0.16% and it is not on CISA KEV.

Technical ContextAI

WEBrick is the pure-Ruby HTTP server library historically bundled with the Ruby standard library and commonly used for local development, testing, and lightweight embedded services. The flaw is a classic CWE-444 (Inconsistent Interpretation of HTTP Requests / request smuggling): when a request uses chunked transfer encoding, the trailer section can carry header-like fields, and WEBrick incorrectly folds a trailer-supplied Content-Length into the authoritative/canonical request metadata after the body has already been framed. Because HTTP intermediaries determine message boundaries from the initial headers, a second component that honors the trailer-derived Content-Length will disagree on where one request ends and the next begins, allowing a smuggled request to be injected into another connection's stream.

Affected ProductsAI

Ruby WEBrick HTTP server library, all versions up to and including 1.9.2 ('through v1.9.2'), as reported via cve@mitre.org and tracked at https://github.com/ruby/webrick/issues/198 with a fix in https://github.com/ruby/webrick/pull/199. A third-party advisory is available at https://vuldb.com/vuln/376033. No CPE strings were provided in the source data, so exact packaged/gem version enumeration beyond the '<=1.9.2' range is not independently confirmed here.

RemediationAI

Upstream fix available (PR/commit) via https://github.com/ruby/webrick/pull/199; a released, tagged patched version was not provided in the input and is not independently confirmed, so upgrade the webrick gem to the first release incorporating PR #199 once published (track the fix reference and https://github.com/ruby/webrick/issues/198). As a compensating control until patched, avoid exposing WEBrick directly behind a differing HTTP intermediary; if a front-end proxy/CDN is in use, configure it to reject requests that combine Transfer-Encoding: chunked with trailer fields, strip HTTP trailers, and normalize/deny ambiguous Content-Length so the trailer value cannot reach WEBrick (side effect: legitimate trailer-dependent clients, e.g. some gRPC-web or streaming checksums, will break). Where feasible, replace WEBrick with a hardened production server (e.g. Puma) for internet-facing workloads, since WEBrick is primarily intended for development. Review the vuldb advisory at https://vuldb.com/vuln/376033 for tracking.

CVE-2012-0217 HIGH POC
7.2 Jun 12

The x86-64 kernel system-call functionality in Xen 4.1.2 and earlier, as used in Citrix XenServer 6.0.2 and earlier and

CVE-2026-33309 CRITICAL POC
9.9 Mar 19

An authenticated path traversal vulnerability in Langflow's file upload functionality allows attackers to write arbitrar

CVE-2026-48753 CRITICAL POC
9.9 Jun 26

Arbitrary host file write in Incus before 7.1.0 lets a holder of S3 bucket credentials escape the storage volume via a p

CVE-2019-7304 CRITICAL POC
9.8 Apr 23

Canonical snapd before version 2.37.1 incorrectly performed socket owner validation, allowing an attacker to run arbitra

CVE-2026-33186 CRITICAL POC
9.1 Mar 18

An authorization bypass vulnerability in gRPC-Go allows attackers to circumvent path-based access control by sending HTT

CVE-2026-53727 HIGH POC
8.9 Jul 09

Server-side request forgery in the Ruby css_parser gem (< 3.0.0) lets a remote unauthenticated attacker force the parsin

CVE-2026-50180 HIGH POC
8.7 Jul 02

Arbitrary file read in Langroid's SQLChatAgent (<= 0.63.0) lets an attacker who can influence the LLM-generated SQL exfi

CVE-2026-49852 HIGH POC
8.7 Jul 02

Authentication bypass in the joserfc Python JOSE/JWT library (PyPI, versions <= 1.6.7) lets unauthenticated attackers fo

CVE-2026-55245 HIGH POC
8.7 Aug 28

SSRF in the Bifrost AI gateway's multimodal URL-fetch path permits any client that can submit a Bedrock or Vertex provid

CVE-2026-52776 HIGH POC
8.6 Aug 12

URLSecurityValidator SSRF bypass in compliance-trestle <= 4.0.3 allows a network-positioned attacker to reach cloud meta

CVE-2026-71309 HIGH POC
8.6 Aug 05

Path traversal in rclone's `serve restic` REST API allows any attacker with network access to the endpoint to read, crea

CVE-2026-48595 HIGH POC
8.2 Jun 02

Credential leakage in elixir-tesla (Tesla HTTP client for Elixir) versions 1.4.0 through 1.18.2 allows Authorization and

Vendor StatusVendor

SUSE

Severity: Important
Product Status
SUSE Linux Enterprise Desktop 15 SP7 Not-Affected
SUSE Linux Enterprise Desktop 15 SP7 Affected
SUSE Linux Enterprise Desktop 15 SP7 Not-Affected
SUSE Linux Enterprise High Performance Computing 15 SP7 Not-Affected
SUSE Linux Enterprise High Performance Computing 15 SP7 Affected

Share

CVE-2026-38969 vulnerability details – vuln.today

This site uses cookies essential for authentication and security. No tracking or analytics cookies are used. Privacy Policy