Inappropriate Encoding for Output Context Affecting rabbitmq-server package, versions *


Severity

Recommended
0.0
medium
0
10

Based on Red Hat Enterprise Linux security rating.

Threat Intelligence

EPSS
0.52% (42nd percentile)

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  • Snyk IDSNYK-RHEL10-RABBITMQSERVER-19645019
  • published9 Sept 2026
  • disclosed18 Aug 2026

Introduced: 18 Aug 2026

CVE-2026-43971  (opens in a new tab)
CWE-838  (opens in a new tab)

How to fix?

There is no fixed version for RHEL:10 rabbitmq-server.

NVD Description

Note: Versions mentioned in the description apply only to the upstream rabbitmq-server package and not the rabbitmq-server package as distributed by RHEL. See How to fix? for RHEL:10 relevant fixed versions and status.

Improper Encoding or Escaping of Output vulnerability in ninenines cowlib allows Link header directive smuggling via unescaped special characters in cow_link:link/1.

cow_link:do_link/1 in cowlib interpolates the target URI, rel value, and attribute keys directly into the serialized Link: header value without escaping or token-grammar validation. A > byte in target prematurely closes the URI slot, allowing an attacker to append additional link entries with attacker-chosen rel directives. A " or \ in rel escapes the quoted string and opens new parameters. Any byte — including whitespace, =, and " — in an attribute key is emitted verbatim. Because browsers act on Link: directives such as rel="preconnect", rel="preload", and rel="prerender", an attacker who can influence these fields in an application that round-trips parsed Link headers through cow_link:link/1 can force victim browsers to make out-of-band connections to attacker-controlled origins.

This issue affects cowlib: from 2.9.0 before 2.20.0.

CVSS Base Scores

version 3.1