{"id":"CVE-2026-67226","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, Admin-only atom exhaustion: PUT /api/users tags list. settags/2 maps rabbitdatacoercion:toatom/1 over the user's tags list. The 20 MB management …","severity":"medium","cvss":6.9,"cvssVector":"CVSS:4.0/AV:N/AC:L/AT:N/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"],"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-2026-67226","references":[{"url":"https://github.com/rabbitmq/rabbitmq-server/commit/86601c5a6d1c7e41060e3dbd165c88bdc91266ee","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/security/advisories/GHSA-34c7-r8w9-5wv8","label":"security-advisories@github.com"},{"url":"https://github.com/rabbitmq/rabbitmq-server/security/advisories/GHSA-34c7-r8w9-5wv8","label":"134c704f-9b21-4f2e-91b3-4a467353bcc0"},{"url":"https://security.access.redhat.com/data/csaf/v2/vex/2026/cve-2026-67226.json"},{"url":"https://access.redhat.com/security/cve/CVE-2026-67226"},{"url":"https://bugzilla.redhat.com/show_bug.cgi?id=2541518"},{"url":"https://www.cve.org/CVERecord?id=CVE-2026-67226"},{"url":"https://nvd.nist.gov/vuln/detail/CVE-2026-67226"},{"url":"https://access.redhat.com/errata/RHSA-2026:67552"}],"tags":["nvd","cve.org","exploit-available","csaf","vex","red-hat","score-dispute"],"epss":0.00389,"epssPercentile":0.32869,"exploitAvailable":true,"ssvc":{"exploitation":"poc","automatable":"no","technicalImpact":"partial","timestamp":"2026-09-25T19:55:06.667719Z"},"cvssSource":"cna","ingestedAt":"2026-09-25T17:13:14.022Z","patched":["hardened_images"],"scores":{"cna":6.9,"vendor":4.9},"slug":"CVE-2026-67226","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, Admin-only atom exhaustion: PUT /api/users tags list. settags/2 maps rabbitdatacoercion:toatom/1 over the user's tags list. The 20 MB management body limit fits ~3-4M short tag strings. An administrator can crash the node in a single request by creating a user (or importing definitions) with ~1M unique tag administrator. This issue is fixed in versions 4.0.22 and 4.1.14 and 4.2.7.\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-2026-67226.json)","depth":"twilight","depthScore":50,"depthScoreParts":{"impact":38,"likelihood":0.1,"exploitation":12,"ransomware":0},"changes":[{"seq":211166,"id":"CVE-2026-67226","ts":1790367520308,"field":"exploit_available","old":"false","new":"true"}]}