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.

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Fixes

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History

Sat, 26 Sep 2026 11:45:00 +0000

Type Values Removed Values Added
First Time appeared Rabbitmq
Rabbitmq rabbitmq-server
Vendors & Products Rabbitmq
Rabbitmq rabbitmq-server

Fri, 25 Sep 2026 21:30:00 +0000

Type Values Removed Values Added
Metrics ssvc

{'options': {'Automatable': 'no', 'Exploitation': 'none', 'Technical Impact': 'partial'}, 'version': '2.0.3'}


Fri, 25 Sep 2026 16:30:00 +0000

Type Values Removed Values Added
Description 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.
Title RabbitMQ: Non-RFC-conformant cookie name when clearing the auth-mechanism preference
Weaknesses CWE-20
References
Metrics cvssV4_0

{'score': 2.3, 'vector': 'CVSS:4.0/AV:N/AC:L/AT:P/PR:N/UI:P/VC:N/VI:L/VA:N/SC:N/SI:N/SA:N'}


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cve-icon MITRE

Status: PUBLISHED

Assigner: GitHub_M

Published:

Updated: 2026-09-25T19:53:58.560Z

Reserved: 2026-07-28T19:50:39.438Z

Link: CVE-2026-67234

cve-icon Vulnrichment

Updated: 2026-09-25T19:53:55.201Z

cve-icon NVD

Status : Received

Published: 2026-09-25T17:17:11.743

Modified: 2026-09-25T20:17:38.987

Link: CVE-2026-67234

cve-icon Redhat

No data.

cve-icon OpenCVE Enrichment

Updated: 2026-09-26T11:30:09Z

Weaknesses