{"id":"CVE-2026-67227","title":"RabbitMQ is a messaging and streaming broker","summary":"RabbitMQ is a messaging and streaming broker. From 4.0.0 until 4.0.22 and 4.1.14 and 4.2.7 and 4.3.1, Atom exhaustion: toatom on global-parameter :name. resourceexists/2 (and the PUT/DELETE handlers) call rabbitdatacoercion:toatom/1 on t…","severity":"medium","cvss":5.9,"cvssVector":"CVSS:4.0/AV:N/AC:L/AT:P/PR:H/UI:N/VC:N/VI:N/VA:H/SC:N/SI:N/SA:N","cwe":["CWE-400","CWE-770"],"vendor":"rabbitmq","product":"rabbitmq-server","affected":["rabbitmq-server >= 4.0.0, < 4.0.22","rabbitmq-server >= 4.1.0, < 4.1.14","rabbitmq-server >= 4.2.0, < 4.2.7","rabbitmq-server >= 4.3.0, < 4.3.1"],"published":"2026-09-25","updated":"2026-09-28","sourceUpdated":"2026-09-28T14:38:38.163","source":"NVD","sourceUrl":"https://nvd.nist.gov/vuln/detail/CVE-2026-67227","references":[{"url":"https://github.com/rabbitmq/rabbitmq-server/commit/8fbe6d8112427e85fb9a9206b3eb6e9a3ddd3e39","label":"security-advisories@github.com"},{"url":"https://github.com/rabbitmq/rabbitmq-server/commit/fc591e7ee27a29657ca960930acefd3e4217e007","label":"security-advisories@github.com"},{"url":"https://github.com/rabbitmq/rabbitmq-server/releases/tag/v4.2.7","label":"security-advisories@github.com"},{"url":"https://github.com/rabbitmq/rabbitmq-server/releases/tag/v4.3.1","label":"security-advisories@github.com"},{"url":"https://github.com/rabbitmq/rabbitmq-server/security/advisories/GHSA-q7x8-97rh-cr24","label":"security-advisories@github.com"},{"url":"https://security.access.redhat.com/data/csaf/v2/vex/2026/cve-2026-67227.json"},{"url":"https://access.redhat.com/security/cve/CVE-2026-67227"},{"url":"https://bugzilla.redhat.com/show_bug.cgi?id=2541519"},{"url":"https://www.cve.org/CVERecord?id=CVE-2026-67227"},{"url":"https://nvd.nist.gov/vuln/detail/CVE-2026-67227"},{"url":"https://access.redhat.com/errata/RHSA-2026:67552"}],"tags":["nvd","cve.org","csaf","vex","red-hat"],"epss":0.00378,"epssPercentile":0.31578,"ssvc":{"exploitation":"none","automatable":"no","technicalImpact":"partial","timestamp":"2026-09-25T17:47:50.875187Z"},"cvssSource":"cna","ingestedAt":"2026-09-25T17:13:14.021Z","patched":["hardened_images"],"scores":{"cna":5.9,"vendor":4.9},"slug":"CVE-2026-67227","body":"## Overview\n\nRabbitMQ is a messaging and streaming broker. From 4.0.0 until 4.0.22 and 4.1.14 and 4.2.7 and 4.3.1, Atom exhaustion: toatom on global-parameter :name. resourceexists/2 (and the PUT/DELETE handlers) call rabbitdatacoercion:toatom/1 on the :name URL path segment. toatom/1 uses binarytoatom/2 (unsafe). The endpoint requires policymaker (not management, but below A user with the policymaker tag can crash the node by exhausting the atom table via repeated requests to /api/global-parameters/:name with unique :name Management plugin enabled policymaker tag ~1M HTTP. This issue is fixed in versions 4.0.22 and 4.1.14 and 4.2.7 and 4.3.1.\n\n## Remediation\n\nRefer to the linked advisories for vendor-supplied fixes and affected version ranges.\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** · Moderate · 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-2026-67227.json)","depth":"sunlit","depthScore":33,"depthScoreParts":{"impact":32.5,"likelihood":0.1,"exploitation":0,"ransomware":0},"changes":[]}