{"id":"BIT-rabbitmq-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":["CVE-2026-67234","GHSA-q286-p3m9-j69f"],"modified":"2026-10-01T10:11:09.383463911Z","published":"2026-10-01T09:33:28.500Z","database_specific":{"cpes":["cpe:2.3:a:vmware:rabbitmq:*:*:*:*:*:*:*:*"],"severity":"Low"},"references":[{"type":"WEB","url":"https://github.com/rabbitmq/rabbitmq-server/commit/149cb59d618cefa83c6deb02dbbb1e8a7a2bc968"},{"type":"WEB","url":"https://github.com/rabbitmq/rabbitmq-server/commit/baac0aaf170efeb4f124ee36b8417274fa8dcc1a"},{"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":"WEB","url":"https://github.com/rabbitmq/rabbitmq-server/security/advisories/GHSA-q286-p3m9-j69f"},{"type":"WEB","url":"https://nvd.nist.gov/vuln/detail/CVE-2026-67234"}],"affected":[{"package":{"name":"rabbitmq","ecosystem":"Bitnami","purl":"pkg:bitnami/rabbitmq"},"ranges":[{"type":"SEMVER","events":[{"introduced":"4.2.0"},{"fixed":"4.2.8"},{"introduced":"4.3.0"},{"fixed":"4.3.2"}]}],"database_specific":{"source":"https://github.com/bitnami/vulndb/tree/main/data/rabbitmq/BIT-rabbitmq-2026-67234.json"},"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/E:X/CR:X/IR:X/AR:X/MAV:X/MAC:X/MAT:X/MPR:X/MUI:X/MVC:X/MVI:X/MVA:X/MSC:X/MSI:X/MSA:X/S:X/AU:X/R:X/V:X/RE:X/U:X"}]}],"schema_version":"1.9.0"}