{"id":"CVE-2026-66078","title":"RabbitMQ is a messaging and streaming broker","summary":"RabbitMQ is a messaging and streaming broker. From 3.13.0 until 3.13.15 and 4.0.20 and 4.1.11 and 4.2.6, protected tag bypass via bulk-delete. dELETE /api/users/:name refuses to delete users tagged protected (rabbitmgmtwmuser:deleteresou…","severity":"medium","cvss":5.5,"cvssVector":"CVSS:3.1/AV:N/AC:L/PR:H/UI:N/S:U/C:N/I:L/A:H","cwe":["CWE-862","CWE-420"],"vendor":"broadcom","product":"rabbitmq_server","affected":["rabbitmq_server >= 3.13.0, < 3.13.15","rabbitmq_server >= 4.0.0, < 4.0.20","rabbitmq_server >= 4.1.0, < 4.1.11","rabbitmq_server >= 4.2.0, < 4.2.6"],"patched":["rabbitmq_server 4.2.6"],"published":"2026-09-25","updated":"2026-10-15","sourceUpdated":"2026-10-15T20:07:28.857","source":"NVD","sourceUrl":"https://nvd.nist.gov/vuln/detail/CVE-2026-66078","references":[{"url":"https://github.com/rabbitmq/rabbitmq-server/commit/e5b890a64b42ec1f79a8e9d735512150cf77479c","label":"security-advisories@github.com"},{"url":"https://github.com/rabbitmq/rabbitmq-server/releases/tag/v4.2.6","label":"security-advisories@github.com"},{"url":"https://github.com/rabbitmq/rabbitmq-server/security/advisories/GHSA-j9m2-hw6x-rqr9","label":"security-advisories@github.com"},{"url":"https://github.com/rabbitmq/rabbitmq-server/security/advisories/GHSA-j9m2-hw6x-rqr9","label":"134c704f-9b21-4f2e-91b3-4a467353bcc0"},{"url":"https://security.access.redhat.com/data/csaf/v2/vex/2026/cve-2026-66078.json"},{"url":"https://access.redhat.com/security/cve/CVE-2026-66078"},{"url":"https://bugzilla.redhat.com/show_bug.cgi?id=2541499"},{"url":"https://www.cve.org/CVERecord?id=CVE-2026-66078"},{"url":"https://nvd.nist.gov/vuln/detail/CVE-2026-66078"},{"url":"https://access.redhat.com/errata/RHSA-2026:67552"}],"tags":["nvd","cve.org","exploit-available","csaf","vex","red-hat","score-dispute"],"epss":0.0043,"epssPercentile":0.37089,"exploitAvailable":true,"ssvc":{"exploitation":"poc","automatable":"yes","technicalImpact":"total","timestamp":"2026-09-29T19:23:41.607515Z"},"scores":{"nvd":5.5,"cna":2.1,"vendor":2.7},"ingestedAt":"2026-09-25T17:13:14.028Z","slug":"CVE-2026-66078","body":"## Overview\n\nRabbitMQ is a messaging and streaming broker. From 3.13.0 until 3.13.15 and 4.0.20 and 4.1.11 and 4.2.6, protected tag bypass via bulk-delete. dELETE /api/users/:name refuses to delete users tagged protected (rabbitmgmtwmuser:deleteresource/2 checks isprotecteduser). POST /api/users/bulk-delete iterates the supplied username list and calls rabbitauthbackendinternal:deleteuser/2 directly , that function has no protected-tag check , so the guard is silently An administrator can delete protected-tagged service accounts via the bulk endpoint, bypassing a safeguard the test suite confirms is rabbitmqmanagement enabled Attacker has the administrator tag A protected-tagged user. This issue is fixed in versions 3.13.15 and 4.0.20 and 4.1.11 and 4.2.6.\n\n## Affected\n\n- `rabbitmq_server >= 3.13.0, < 3.13.15`\n- `rabbitmq_server >= 4.0.0, < 4.0.20`\n- `rabbitmq_server >= 4.1.0, < 4.1.11`\n- `rabbitmq_server >= 4.2.0, < 4.2.6`\n\n## Remediation\n\nUpgrade past the affected range:\n\n- `rabbitmq_server 4.2.6`\n\n## Vendor advisories\n\n- **RHSA-2026:67552** · Red Hat · fixed in: Red Hat Hardened Images · released 2026-09-15 · [advisory](https://access.redhat.com/errata/RHSA-2026:67552)\n- **Red Hat VEX** · Low · affected: Red Hat Hardened Images, Red Hat OpenStack Platform 13 (Queens), Red Hat OpenStack Platform 16.2, Red Hat OpenStack Platform 17.1, Red Hat OpenStack Platform 18.0 · no fix planned: Red Hat OpenStack Platform 13 (Queens), Red Hat OpenStack Platform 16.2, Red Hat OpenStack Platform 17.1, Red Hat Hardened Images, … · updated 2026-10-17 · [vex](https://security.access.redhat.com/data/csaf/v2/vex/2026/cve-2026-66078.json)","depth":"twilight","depthScore":42,"depthScoreParts":{"impact":30.3,"likelihood":0.1,"exploitation":12,"ransomware":0},"changes":[{"seq":230118,"id":"CVE-2026-66078","ts":1793124792614,"field":"cvss","old":"2.1","new":"5.5"},{"seq":230117,"id":"CVE-2026-66078","ts":1793124792614,"field":"severity","old":"low","new":"medium"},{"seq":213097,"id":"CVE-2026-66078","ts":1790711145093,"field":"exploit_available","old":"false","new":"true"}]}