Go
CVE-2015-5739
CRITICAL
Vulnerability Assessment
| Weakness |
CWE
OWASP Top 10:2025
A06:2025 - Insecure Design
ASVS 5.0
V4 - API and Web Service HTTP request consistency
|
| Impact | CVSS score of 9.8 (CRITICAL). Attack characteristics: network attack vector, low complexity, no privileges required, no user interaction not required. EPSS exploitation probability: 11.88%. |
| Exploit ScenarioDerived | A remote attacker could manipulate HTTP request interpretation between frontend and backend servers by sending crafted requests to the affected application. No authentication is required to exploit this vulnerability. |
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Alert meAnalysisAI
The net/http library in net/textproto/reader.go in Go before 1.4.3 does not properly parse HTTP header keys, which allows remote attackers to conduct HTTP request smuggling attacks via a space. Rated critical severity (CVSS 9.8), this vulnerability is remotely exploitable, no authentication required, low attack complexity. Epss exploitation probability 11.9%.
RemediationAI
A vendor patch is available. Apply the latest security update as soon as possible. Enforce strict HTTP parsing, normalize requests at proxy layer, use HTTP/2 end-to-end, reject ambiguous headers.
Affected Packages
Source: OSV (Open Source Vulnerabilities)
Affects your stack
Affects 1 package in go
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Technical ContextAI · show details
This vulnerability is classified as HTTP Request/Response Smuggling (CWE-444), which allows attackers to manipulate HTTP request interpretation between frontend and backend servers. The net/http library in net/textproto/reader.go in Go before 1.4.3 does not properly parse HTTP header keys, which allows remote attackers to conduct HTTP request smuggling attacks via a space instead of a hyphen, as demonstrated by "Content Length" instead of "Content-Length." Affected products include: Golang Go, Fedoraproject Fedora, Redhat Enterprise Linux Server, Redhat Enterprise Linux Server Aus, Redhat Enterprise Linux Server Eus. Version information: before 1.4.3.
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- Exploit and PoC references, threat intelligence from 22 sources
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Severity by source
AV:N/AC:L/PR:N/UI:N/S:U/C:H/I:H/A:H
Primary rating from NVD · only source for this CVE.
CVSS VectorNVD
DescriptionCVE.org
The net/http library in net/textproto/reader.go in Go before 1.4.3 does not properly parse HTTP header keys, which allows remote attackers to conduct HTTP request smuggling attacks via a space instead of a hyphen, as demonstrated by "Content Length" instead of "Content-Length."
Threat Intelligence Overview
NVD
CVE.org
EPSS
GitHub
How this decision was reached
The engine reads each signal below and applies a fixed list of rules from top to bottom. The first rule that matches sets the recommended action – like a statement, every line is shown.
What every action level means
SSVC AssessmentENISA
Priority Score
Attack Technique
HTTP request smuggling exploits inconsistencies in how front-end and back-end servers parse HTTP message boundaries.
Information disclosure occurs when an application unintentionally exposes sensitive data that aids attackers in reconnaissance or directly compromises security.
Affected Products (CPE)CVE.org
Denial of service against HTTP/2 server implementations allows remote unauthenticated attackers to exhaust server resour
The net/http package in Go through 1.6 does not attempt to address RFC 3875 section 4.1.18 namespace conflicts and there
Critical certificate validation bypass in Go crypto/tls during session resumption. If ClientCAs or RootCAs fields are mu
net/url in Go before 1.11.13 and 1.12.x before 1.12.8 mishandles malformed hosts in URLs, leading to an authorization by
Casdoor through 4.4.0 exposes its instance-wide built-in JWT signing private key unmasked through the /api/get-certs and
Host header injection in Nezha 2.2.3's OAuth2 redirect endpoint (/api/v1/oauth2/{provider}) allows an unauthenticated re
Session cross-wiring in SUSE NeuVector before 5.6.1 allows an unauthenticated remote attacker to obtain another user's a
Unauthenticated path traversal in Uber Kraken through 0.1.29 allows remote attackers to read files outside the configure
The "go get" implementation in Go 1.9.4, when the -insecure command-line option is used, does not validate the import pa
Denial of service in Temporal Server allows an authenticated caller holding at least namespace read permission to crash
Account takeover in Klever-Go's KleverUpdateAccountPermission built-in (all versions prior to 1.7.20) allows an attacker
Maliciously crafted on-chain account names processed by Klever-Go prior to 1.7.20 are spliced into Elasticsearch _bulk r
Exploit-DB