Unchecked Return Value in RabbitMQ Server - CVE-2026-67409
Published: July 24, 2026 / Updated: September 28, 2026
Vulnerability identifier: #VU139296
CSH Severity: Medium
CVSS v4: 8.7 [CVSS:4.0/AV:N/AC:L/AT:N/PR:N/UI:N/VC:N/VI:N/VA:H/SC:N/SI:N/SA:N]
CVE-ID: CVE-2026-67409
CWE-ID: CWE-252
Exploitation vector: Remote access
Exploit availability:
No public exploit available
Vulnerability details
The vulnerability allows a remote attacker to cause a denial of service.
The vulnerability exists due to unchecked return value in the JWKS key fetching mechanism in uaa_jwt.erl when processing JWKS endpoint responses during signing key refresh. A remote attacker can send a crafted JWT with an unknown kid value to cause a denial of service.
Exploitation requires RabbitMQ to be configured with OAuth2 authentication using JWKS-based key discovery, and the JWKS endpoint must return an error response with a valid JSON body that lacks a keys field.
Affected software
RabbitMQ Server
openEuler
rabbitmq-server
openEuler
rabbitmq-server
How to mitigate CVE-2026-67409
Install security update from vendor's website.
RabbitMQ Server - addressed in versions 3.13.18, 4.0.23, 4.1.14, 4.2.9, 4.3.3
rabbitmq-server - update to 3.9.23-4
rabbitmq-server - update to 3.9.23-4