{"id":"BIT-rabbitmq-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":["CVE-2026-67219","GHSA-m8pg-4x2h-jvgr"],"modified":"2026-10-01T10:11:10.919102505Z","published":"2026-10-01T09:33:03.838Z","database_specific":{"cpes":["cpe:2.3:a:vmware:rabbitmq:*:*:*:*:*:*:*:*"],"severity":"Medium"},"references":[{"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":"WEB","url":"https://github.com/rabbitmq/rabbitmq-server/security/advisories/GHSA-m8pg-4x2h-jvgr"},{"type":"WEB","url":"https://nvd.nist.gov/vuln/detail/CVE-2026-67219"}],"affected":[{"package":{"name":"rabbitmq","ecosystem":"Bitnami","purl":"pkg:bitnami/rabbitmq"},"ranges":[{"type":"SEMVER","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"},{"introduced":"4.2.0"},{"fixed":"4.2.6"}]}],"database_specific":{"source":"https://github.com/bitnami/vulndb/tree/main/data/rabbitmq/BIT-rabbitmq-2026-67219.json"},"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/E:X/CR:X/IR:X/AR:X/MAV:X/MAC:X/MAT:X/MPR:X/MUI:X/MVC:X/MVI:X/MVA:X/MSC:X/MSI:X/MSA:X/S:X/AU:X/R:X/V:X/RE:X/U:X"}]}],"schema_version":"1.9.0"}