{"schema":"threatline.record/2","record":{"id":"CVE-2026-67411","aliases":["GHSA-4r6f-9cpw-f6g6"],"summary":"RabbitMQ: Web MQTT with PROXY Protocol enabled: a loopback-only user permission bypass","details":"RabbitMQ is a messaging and streaming broker. From 3.13.0 until 3.13.18, 4.0.23, 4.1.14, 4.2.9, and 4.3.3, native MQTT and MQTT over WebSocket behind a trusted PROXY Protocol frontend could lose the proxy-derived client address before the MQTT authentication path checked loopback_users, causing the frontend-to-broker address to be treated as loopback. An attacker who can reach the trusted frontend and has valid credentials for a loopback-restricted account can therefore bypass the source-address restriction; the issue does not bypass password authentication. This issue is fixed in versions 3.13.18, 4.0.23, 4.1.14, 4.2.9, and 4.3.3.","categories":["Unclassified"],"product":"rabbitmq-server","vendor":"rabbitmq","ecosystem":null,"affected_ranges":[{"source":"CVE List","source_url":"https://www.cve.org/CVERecord?id=CVE-2026-67411","source_modified_at":"2026-09-25T16:55:42.722Z","fetched_at":"2026-10-23T18:52:38.922436Z","product":"rabbitmq-server","vendor":"rabbitmq","versions":[{"version":">= 4.3.0, < 4.3.3","status":"affected"},{"version":">= 4.2.0, < 4.2.9","status":"affected"},{"version":">= 4.1.0, < 4.1.14","status":"affected"},{"version":">= 4.0.0, < 4.0.23","status":"affected"},{"version":">= 3.13.0, < 3.13.18","status":"affected"}],"defaultStatus":null}],"fixed_versions":[],"cvss":6,"severity":"Medium","kev":{"listed":false},"epss":{"probability":0.00318,"percentile":0.23526,"score_date":"2026-10-23"},"published_at":"2026-09-25T16:26:33.880Z","modified_at":"2026-09-25T16:55:42.722Z","provenance":[{"source":"CVE List","url":"https://www.cve.org/CVERecord?id=CVE-2026-67411","fetched_at":"2026-10-23T18:52:38.922436Z","source_modified_at":"2026-09-25T16:55:42.722Z"},{"source":"EPSS","url":"https://api.first.org/data/v1/epss?cve=CVE-2026-67411","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-4r6f-9cpw-f6g6","tags":["exploit"]},{"source":"CVE List","url":"https://github.com/rabbitmq/rabbitmq-server/commit/a7528314840c4f8dc9904684f9f97ffa7aac6349","tags":["x_refsource_MISC"]},{"source":"CVE List","url":"https://github.com/rabbitmq/rabbitmq-server/commit/edbead0eabbd65925d0dc914a22d6a29e155e646","tags":["x_refsource_MISC"]},{"source":"CVE List","url":"https://github.com/rabbitmq/rabbitmq-server/releases/tag/v4.2.9","tags":["x_refsource_MISC"]},{"source":"CVE List","url":"https://github.com/rabbitmq/rabbitmq-server/releases/tag/v4.3.3","tags":["x_refsource_MISC"]}],"locations":[],"motoko_assessment":{"status":"requires_architecture_review","automatic_remediation":false},"cve_state":"PUBLISHED","cvss_source":"CVE List","ssvc":{"exploitation":"poc","automatable":"no","technical_impact":"partial","assessed_at":"2026-09-25T16:55:11.064286Z"},"classification":{"method":"product-first software-layer rules","rules_version":"2.1","matched_on":null,"confidence":"unknown","reviewed":false},"change_timestamp":"2026-09-25T16:55:42.722Z","content_hash":"e8b84d8f3eae212ae4b55efca14a04926851eaa1776ab90a04a45550c14b692f"}}