{"schema":"threatline.record/2","record":{"id":"CVE-2026-66071","aliases":["GHSA-89p2-f5cv-x5cg"],"summary":"RabbitMQ: Atom exhaustion: OAuth2 JWT tag: scope values","details":"RabbitMQ is a messaging and streaming broker. From 3.13.0 until 3.13.15 and 4.0.22 and 4.1.11 and 4.2.6 and 4.3.1, Atom exhaustion: OAuth2 JWT tag: scope values. extractscopes/1 parses scopes of the form .tag: and calls rabbitdatacoercion:toatom() to convert to a tag atom. The token signature is verified first, so the attacker cannot forge scopes , but in IdP configurations where scope content is user-influenced, each login with a novel tag value leaks one In deployments where users can influence the scopes included in their IdP-issued JWT rabbitmqauthbackendoauth2 enabled IdP permits attacker-influenced scope values in signed tokens. This issue is fixed in versions 3.13.15 and 4.0.22 and 4.1.11 and 4.2.6 and 4.3.1.","categories":["Unclassified"],"product":"rabbitmq-server","vendor":"rabbitmq","ecosystem":null,"affected_ranges":[{"source":"CVE List","source_url":"https://www.cve.org/CVERecord?id=CVE-2026-66071","source_modified_at":"2026-09-25T17:53:13.500Z","fetched_at":"2026-10-23T18:52:38.922436Z","product":"rabbitmq-server","vendor":"rabbitmq","versions":[{"version":">= 3.13.0, < 3.13.15","status":"affected"},{"version":">= 4.0.0, < 4.0.22","status":"affected"},{"version":">= 4.1.0, < 4.1.11","status":"affected"},{"version":">= 4.2.0, < 4.2.6","status":"affected"},{"version":">= 4.3.0, < 4.3.1","status":"affected"}],"defaultStatus":null}],"fixed_versions":[],"cvss":6,"severity":"Medium","kev":{"listed":false},"epss":{"probability":0.00475,"percentile":0.40085,"score_date":"2026-10-23"},"published_at":"2026-09-25T16:11:07.278Z","modified_at":"2026-09-25T17:53:13.500Z","provenance":[{"source":"CVE List","url":"https://www.cve.org/CVERecord?id=CVE-2026-66071","fetched_at":"2026-10-23T18:52:38.922436Z","source_modified_at":"2026-09-25T17:53:13.500Z"},{"source":"EPSS","url":"https://api.first.org/data/v1/epss?cve=CVE-2026-66071","fetched_at":"2026-10-23T18:42:43.628194Z","source_modified_at":"2026-10-23"}],"sources":["CVE List","EPSS"],"references":[{"source":"CVE List","url":"https://github.com/rabbitmq/rabbitmq-server/security/advisories/GHSA-89p2-f5cv-x5cg","tags":["x_refsource_CONFIRM"]},{"source":"CVE List","url":"https://github.com/rabbitmq/rabbitmq-server/commit/9a44124d9c932d6fc7d2a3b945e5a143e547bcb6","tags":["x_refsource_MISC"]},{"source":"CVE List","url":"https://github.com/rabbitmq/rabbitmq-server/commit/c5690583a53789a3bf00cca508b43e8246db0d11","tags":["x_refsource_MISC"]},{"source":"CVE List","url":"https://github.com/rabbitmq/rabbitmq-server/releases/tag/v4.2.6","tags":["x_refsource_MISC"]},{"source":"CVE List","url":"https://github.com/rabbitmq/rabbitmq-server/releases/tag/v4.3.1","tags":["x_refsource_MISC"]}],"locations":[],"motoko_assessment":{"status":"requires_architecture_review","automatic_remediation":false},"cve_state":"PUBLISHED","cvss_source":"CVE List","ssvc":{"exploitation":"none","automatable":"no","technical_impact":"partial","assessed_at":"2026-09-25T17:53:05.694643Z"},"classification":{"method":"product-first software-layer rules","rules_version":"2.1","matched_on":null,"confidence":"unknown","reviewed":false},"change_timestamp":"2026-09-25T17:53:13.500Z","content_hash":"0e351fca50a3700be2a254266c65c8663bda7715b4a0714b808955c7ba113300"}}