Input validation error in RabbitMQ Server - CVE-2026-57220
Published: June 25, 2026
Vulnerability identifier: #VU135149
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-2026-57220
CWE-ID: CWE-20
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 improper input validation in rabbit_stream_core when processing oversized stream frames during authentication before Tune negotiation. A remote attacker can send oversized partial frames to cause a denial of service.
Only deployments with the first-party rabbitmq_stream listener enabled and reachable on port 5552 are vulnerable.
Affected software
RabbitMQ Server
How to mitigate CVE-2026-57220
Install security update from vendor's website.
RabbitMQ Server - update to 4.2.6