Vulnerability Details 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.
Exploit prediction scoring system (EPSS) score
EPSS Score 0.006
EPSS Ranking 45.6%
CVSS Severity
CVSS v3 Score 4.3
References
- https://github.com/rabbitmq/rabbitmq-server/commit/149cb59d618cefa83c6deb02dbbb1e8a7a2bc968
- https://github.com/rabbitmq/rabbitmq-server/commit/baac0aaf170efeb4f124ee36b8417274fa8dcc1a
- https://github.com/rabbitmq/rabbitmq-server/releases/tag/v4.2.8
- https://github.com/rabbitmq/rabbitmq-server/releases/tag/v4.3.2
- https://github.com/rabbitmq/rabbitmq-server/security/advisories/GHSA-q286-p3m9-j69f
Products affected by CVE-2026-67234
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cpe:2.3:a:broadcom:rabbitmq_server:4.2.0
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cpe:2.3:a:broadcom:rabbitmq_server:4.2.1
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cpe:2.3:a:broadcom:rabbitmq_server:4.2.2
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cpe:2.3:a:broadcom:rabbitmq_server:4.2.3
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cpe:2.3:a:broadcom:rabbitmq_server:4.2.4
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cpe:2.3:a:broadcom:rabbitmq_server:4.2.5
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cpe:2.3:a:broadcom:rabbitmq_server:4.2.6
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cpe:2.3:a:broadcom:rabbitmq_server:4.2.7
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cpe:2.3:a:broadcom:rabbitmq_server:4.3.0
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cpe:2.3:a:broadcom:rabbitmq_server:4.3.1