{"id":"CVE-2026-67219","summary":"RabbitMQ: Consistent-hash exchange unbounded weight","details":"RabbitMQ is a messaging and streaming broker. Prior to versions 3.13.15, 4.0.20, 4.1.11, 4.2.6, and 4.3.0, add_binding/3 parses the routing key as an integer weight N and computes ring positions with lists:seq(NextN0, NextN0 + N - 1). validate_binding/2 only checks N \u003e= 1 , no upper bound. The resulting list is stored in the exchange's Khepri record, replicated cluster-wide, and reloaded on restart. A user with write permission on a consistent-hash exchange and read on a queue can create a binding whose routing key (the hash-ring weight) is an arbitrarily large integer. The broker allocates a list of that many integers via lists:seq/2 and persists it to Khepri across all cluster nodes , a single binding with weight 100000000 allocates ~800 MB on every node and survives restarts. Preconditions include rabbitmq_consistent_hash_exchange plugin enabled write permission on a consistent-hash exchange + read on a queue (standard binding perms). This issue is fixed in versions 3.13.15, 4.0.20, 4.1.11, 4.2.6, and 4.3.0.","aliases":["GHSA-m8pg-4x2h-jvgr"],"modified":"2026-09-24T11:45:21.261320876Z","published":"2026-09-23T20:38:42.653Z","database_specific":{"osv_generated_from":"https://github.com/CVEProject/cvelistV5/tree/main/cves/2026/67xxx/CVE-2026-67219.json","unresolved_ranges":[{"extracted_events":[{"introduced":"3.13.0"},{"fixed":"3.13.15"},{"introduced":"4.0.0"},{"fixed":"4.0.20"},{"introduced":"4.1.0"},{"fixed":"4.1.11"}],"source":"AFFECTED_FIELD"}],"cna_assigner":"GitHub_M","cwe_ids":["CWE-770"]},"references":[{"type":"ADVISORY","url":"https://github.com/CVEProject/cvelistV5/tree/main/cves/2026/67xxx/CVE-2026-67219.json"},{"type":"WEB","url":"https://github.com/rabbitmq/rabbitmq-server/releases/tag/v4.2.6"},{"type":"WEB","url":"https://github.com/rabbitmq/rabbitmq-server/releases/tag/v4.3.0"},{"type":"ADVISORY","url":"https://github.com/rabbitmq/rabbitmq-server/security/advisories/GHSA-m8pg-4x2h-jvgr"},{"type":"ADVISORY","url":"https://nvd.nist.gov/vuln/detail/CVE-2026-67219"}],"affected":[{"ranges":[{"type":"GIT","repo":"https://github.com/rabbitmq/rabbitmq-server","events":[{"introduced":"95c501fbad76c66156346cf364d158d6e30aa4d9"},{"fixed":"8a56c37f099a7bf609a555de3f0ff8ed23964d20"}],"database_specific":{"extracted_events":[{"introduced":"4.2.0"},{"fixed":"4.2.6"}],"source":"AFFECTED_FIELD"}}],"versions":["v4.2.5","v4.2.4","v4.2.3","v4.2.2","v4.2.1","v4.2.0"],"database_specific":{"source":"https://storage.googleapis.com/cve-osv-conversion/osv-output/CVE-2026-67219.json"}}],"schema_version":"1.9.0","severity":[{"type":"CVSS_V4","score":"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"}]}