{"id":"CVE-2026-66071","revision":"c04982042081400fbfacaf7b4a44db5d","records":[{"revision":"c04982042081400fbfacaf7b4a44db5d","observedAt":"2026-10-23T15:48:27.903+00:00","statement":{"source":"cve-program","id":"CVE-2026-66071","aliases":[],"title":"RabbitMQ: Atom exhaustion: OAuth2 JWT tag: scope values","description":"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.","state":0,"publishedAt":"2026-09-25T16:11:07.278+00:00","modifiedAt":"2026-09-25T17:53:13.5+00:00","affected":[{"ecosystem":"Vendor product","name":"rabbitmq-server","ranges":[],"versions":[],"rawVersionEvidence":"{\n                    \"vendor\": \"rabbitmq\",\n                    \"product\": \"rabbitmq-server\",\n                    \"versions\": [\n                        {\n                            \"version\": \">= 3.13.0, < 3.13.15\",\n                            \"status\": \"affected\"\n                        },\n                        {\n                            \"version\": \">= 4.0.0, < 4.0.22\",\n                            \"status\": \"affected\"\n                        },\n                        {\n                            \"version\": \">= 4.1.0, < 4.1.11\",\n                            \"status\": \"affected\"\n                        },\n                        {\n                            \"version\": \">= 4.2.0, < 4.2.6\",\n                            \"status\": \"affected\"\n                        },\n                        {\n                            \"version\": \">= 4.3.0, < 4.3.1\",\n                            \"status\": \"affected\"\n                        }\n                    ]\n                }"}],"metrics":[{"system":"CVSS 4.0","vector":"CVSS:4.0/AV:N/AC:L/AT:P/PR:L/UI:N/VC:N/VI:N/VA:H/SC:N/SI:N/SA:N","score":6,"severity":"MEDIUM"}],"references":["https://github.com/rabbitmq/rabbitmq-server/security/advisories/GHSA-89p2-f5cv-x5cg","https://github.com/rabbitmq/rabbitmq-server/commit/9a44124d9c932d6fc7d2a3b945e5a143e547bcb6","https://github.com/rabbitmq/rabbitmq-server/commit/c5690583a53789a3bf00cca508b43e8246db0d11","https://github.com/rabbitmq/rabbitmq-server/releases/tag/v4.2.6","https://github.com/rabbitmq/rabbitmq-server/releases/tag/v4.3.1"],"sourceUrl":"https://www.cve.org/CVERecord?id=CVE-2026-66071","license":"CVE Program Terms of Use","key":"cve-program:CVE-2026-66071","identifiers":["CVE-2026-66071"]},"retained":false,"historicalAffected":[]}],"coverage":[]}