Insufficient Session Expiration in RabbitMQ Server - CVE-2026-67242
Published: July 24, 2026 / Updated: September 28, 2026
Vulnerability identifier: #VU139286
CSH Severity: Medium
CVSS v4: 6.9 [CVSS:4.0/AV:N/AC:L/AT:N/PR:N/UI:N/VC:L/VI:L/VA:N/SC:N/SI:N/SA:N]
CVE-ID: CVE-2026-67242
CWE-ID: CWE-613
Exploitation vector: Remote access
Exploit availability:
No public exploit available
Vulnerability details
The vulnerability allows a remote attacker to bypass token-expiry checks and retain access with an expired token.
The vulnerability exists due to improper expiration handling in rabbit_auth_backend_oauth2 token expiry validation when processing OAuth2 tokens with a floating-point exp claim. A remote attacker can present a previously valid signed token with a float exp value to bypass token-expiry checks and retain access with an expired token.
Exploitation requires the OAuth2 backend to be enabled, an identity provider that emits exp as a JSON float, and possession of a previously valid signed token.
Affected software
RabbitMQ Server
How to mitigate CVE-2026-67242
Install security update from vendor's website.
RabbitMQ Server - addressed in versions 4.2.9, 4.3.3