{"id":"CVE-2026-67234","summary":"RabbitMQ: Non-RFC-conformant cookie name when clearing the auth-mechanism preference","details":"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.","aliases":["GHSA-q286-p3m9-j69f"],"modified":"2026-09-27T03:47:33.283472957Z","published":"2026-09-25T16:03:38.161Z","database_specific":{"cna_assigner":"GitHub_M","cwe_ids":["CWE-20"],"osv_generated_from":"https://github.com/CVEProject/cvelistV5/tree/main/cves/2026/67xxx/CVE-2026-67234.json"},"references":[{"type":"WEB","url":"https://github.com/rabbitmq/rabbitmq-server/releases/tag/v4.2.8"},{"type":"WEB","url":"https://github.com/rabbitmq/rabbitmq-server/releases/tag/v4.3.2"},{"type":"ADVISORY","url":"https://github.com/CVEProject/cvelistV5/tree/main/cves/2026/67xxx/CVE-2026-67234.json"},{"type":"ADVISORY","url":"https://github.com/rabbitmq/rabbitmq-server/security/advisories/GHSA-q286-p3m9-j69f"},{"type":"ADVISORY","url":"https://nvd.nist.gov/vuln/detail/CVE-2026-67234"},{"type":"FIX","url":"https://github.com/rabbitmq/rabbitmq-server/commit/149cb59d618cefa83c6deb02dbbb1e8a7a2bc968"},{"type":"FIX","url":"https://github.com/rabbitmq/rabbitmq-server/commit/baac0aaf170efeb4f124ee36b8417274fa8dcc1a"}],"affected":[{"ranges":[{"type":"GIT","repo":"https://github.com/rabbitmq/rabbitmq-server","events":[{"introduced":"95c501fbad76c66156346cf364d158d6e30aa4d9"},{"introduced":"1929eeadf9b2bac12c5434fb56884ef27370580e"},{"fixed":"8b611c9f4bd2d1615ef855cdf1459da3196d4d3c"},{"fixed":"a509158b1b1e21c892a7f1dacbe0d158076dc7b8"},{"fixed":"149cb59d618cefa83c6deb02dbbb1e8a7a2bc968"},{"fixed":"baac0aaf170efeb4f124ee36b8417274fa8dcc1a"}],"database_specific":{"extracted_events":[{"introduced":"4.2.0"},{"fixed":"4.2.8"},{"introduced":"4.3.0"},{"fixed":"4.3.2"}],"source":["AFFECTED_FIELD","REFERENCES"]}}],"versions":["v4.2.7","v4.3.1","v4.2.6","v4.3.0","v4.2.5","v4.2.4","v4.2.3","v4.2.2","v4.2.1","v4.2.0"],"database_specific":{"source":"https://storage.googleapis.com/cve-osv-conversion/osv-output/CVE-2026-67234.json"}}],"schema_version":"1.9.0","severity":[{"type":"CVSS_V4","score":"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"}]}