CVE-2026-67234

RabbitMQ is a messaging and streaming broker. From 4.2.0 until 4.2.8 and 4.3.2, get_auth_mechanism/1 used term_to_binary/1 on the strict_auth_mechanism or preferred_auth_mechanism atom when clearing the corresponding cookie, producing a non-ASCII cookie name that violates RFC 6265 and can prevent the browser from deleting the preference. The issue is not directly exploitable for code execution or data exfiltration; its security relevance is limited to stale authentication-mechanism preferences persisting across logout and login cycles. This issue is fixed in versions 4.2.8 and 4.3.2.

• CWE-20

• https://github.com/rabbitmq/rabbitmq-server/commit/149cb59d618cefa83c6deb02dbbb1e8a7a2bc968Patch
• https://github.com/rabbitmq/rabbitmq-server/commit/baac0aaf170efeb4f124ee36b8417274fa8dcc1aPatch
• https://github.com/rabbitmq/rabbitmq-server/releases/tag/v4.2.8Release Notes, Patch
• https://github.com/rabbitmq/rabbitmq-server/releases/tag/v4.3.2Release Notes, Patch
• https://github.com/rabbitmq/rabbitmq-server/security/advisories/GHSA-q286-p3m9-j69fVendor Advisory

Published

Sep 25, 2026

Last Modified

Oct 20, 2026

Status

Analyzed

• How Strix found a critical auth bypass in etcdStrix autonomously discovered a critical authentication bypass in etcd, later designated CVE-2026-33413.
• Autonomous PentestingAI agents that find and validate exploitable vulnerabilities like this one across your applications.
• PR ReviewsPentest every pull request so vulnerable code is caught before it ships to production.
• AI Penetration TestingHow AI-driven penetration testing continuously covers your attack surface.

• CVE-2026-67229RabbitMQ is a messaging and streaming broker. Prior to versi…4.9
• CVE-2026-6723The Appointment Booking Calendar — Simply Schedule Appointme…5.3
• CVE-2026-67230RabbitMQ is a messaging and streaming broker. From 3.13.0 un…7.5
• CVE-2026-67231RabbitMQ is a messaging and streaming broker. Prior to versi…9.1
• CVE-2026-67232RabbitMQ is a messaging and streaming broker. Prior to versi…7.5
• CVE-2026-67233RabbitMQ is a messaging and streaming broker. Prior to versi…7.1
• CVE-2026-67235RabbitMQ is a messaging and streaming broker. Prior to versi…6.5
• CVE-2026-67236RabbitMQ is a messaging and streaming broker. From 4.2.0 unt…6.5
• CVE-2026-67237RabbitMQ is a messaging and streaming broker. From 4.2.0 unt…9.3
• CVE-2026-67238RabbitMQ is a messaging and streaming broker. Prior to versi…6.5
• CVE-2026-67239RabbitMQ is a messaging and streaming broker. From 3.13.0 un…5.4
• CVE-2026-67240RabbitMQ is a messaging and streaming broker. Prior to versi…6.5