CVE-2026-67234: CWE-20: Improper Input Validation in rabbitmq rabbitmq-server
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.
AI Analysis
Technical Summary
RabbitMQ versions 4.2.0 up to but not including 4.2.8 and 4.3.0 up to but not including 4.3.2 contain a vulnerability where the get_auth_mechanism/1 function uses term_to_binary/1 on certain atoms to clear cookies, resulting in non-ASCII cookie names that violate RFC 6265. This causes browsers to retain stale authentication-mechanism preferences after logout, potentially confusing authentication state. The issue does not lead to code execution or data leakage. The problem is resolved in versions 4.2.8 and 4.3.2.
Potential Impact
The vulnerability causes stale authentication-mechanism preferences to persist in browsers due to invalid cookie names, which may affect user authentication state consistency. There is no direct risk of code execution, data exfiltration, or other severe impacts. The CVSS 4.0 score is low (2.3), reflecting limited impact.
Mitigation Recommendations
This issue is fixed in rabbitmq-server versions 4.2.8 and 4.3.2. Users should upgrade to these or later versions to resolve the vulnerability. No other mitigation is required as the issue does not pose a direct security threat beyond stale cookie persistence.
CVE-2026-67234: CWE-20: Improper Input Validation in rabbitmq rabbitmq-server
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.
CVSS v4.0
Score 2.3low
Affected software
rabbitmq
rabbitmq-server
pkg:github/rabbitmq/rabbitmq-serverRun on your own infrastructure? Check whether these packages are installed with threat-finder — our free open-source scanner.
Weaknesses
AI-Powered Analysis
Machine-generated threat intelligence
Technical Analysis
RabbitMQ versions 4.2.0 up to but not including 4.2.8 and 4.3.0 up to but not including 4.3.2 contain a vulnerability where the get_auth_mechanism/1 function uses term_to_binary/1 on certain atoms to clear cookies, resulting in non-ASCII cookie names that violate RFC 6265. This causes browsers to retain stale authentication-mechanism preferences after logout, potentially confusing authentication state. The issue does not lead to code execution or data leakage. The problem is resolved in versions 4.2.8 and 4.3.2.
Potential Impact
The vulnerability causes stale authentication-mechanism preferences to persist in browsers due to invalid cookie names, which may affect user authentication state consistency. There is no direct risk of code execution, data exfiltration, or other severe impacts. The CVSS 4.0 score is low (2.3), reflecting limited impact.
Mitigation Recommendations
This issue is fixed in rabbitmq-server versions 4.2.8 and 4.3.2. Users should upgrade to these or later versions to resolve the vulnerability. No other mitigation is required as the issue does not pose a direct security threat beyond stale cookie persistence.
Technical Details
- Data Version
- 5.2
- Assigner Short Name
- GitHub_M
- Date Reserved
- 2026-07-28T19:50:39.438Z
- Cvss Version
- 4.0
- State
- PUBLISHED
Threat ID: 6ab6a25af7a7c54106018e2a
Added to database: 09/25/2026, 16:33:30 UTC
Last enriched: 09/25/2026, 16:48:36 UTC
Last updated: 09/26/2026, 03:44:41 UTC
Views: 13
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