{"id":"CVE-2026-67240","summary":"RabbitMQ: ReDoS via AMQP 1.0 SQL filter LIKE wildcard","details":"RabbitMQ is a messaging and streaming broker. Prior to versions 4.2.7 and 4.3.1, pattern_to_regex maps % -\u003e .*? and _ -\u003e ., then compiles ^...$ with only [unicode]; re:run is called with only [{capture, none}] - no explicit match_limit. A pattern like %_%_..._%X becomes ^.*?..*?.....*?.X$ with overlapping lazy quantifiers. The whole-expression cap is ?MAX_EXPRESSION_LENGTH=4096 chars / ?MAX_TOKENS=200; a LIKE string literal is one token, so ~2000 %_ pairs fit. SQL filters are accepted unconditionally at rabbit_amqp_session.erl:3264 (no feature flag). Evaluated per-message at rabbit_stream_queue.erl:1439. OTP's default 10M match_limit caps each match at ~100-200 ms (not seconds), and the re NIF yields to the scheduler. An authenticated AMQP 1.0 consumer with read+write on a stream queue can cause ~100-200 ms of CPU per delivered message via a crafted LIKE filter, multiplied across thousands of messages and parallel sessions - a substantial backtracking-driven CPU amplification. Preconditions include AMQP 1.0 with stream queues in use Attacker can attach a receiver with a filter (read permission) and publish messages with long property values (write permission). This issue is fixed in versions 4.2.7 and 4.3.1.","aliases":["GHSA-59c5-553c-57m2"],"modified":"2026-09-25T03:48:38.000407538Z","published":"2026-09-23T20:19:22.703Z","database_specific":{"cwe_ids":["CWE-1333"],"osv_generated_from":"https://github.com/CVEProject/cvelistV5/tree/main/cves/2026/67xxx/CVE-2026-67240.json","cna_assigner":"GitHub_M"},"references":[{"type":"WEB","url":"https://github.com/rabbitmq/rabbitmq-server/releases/tag/v4.2.7"},{"type":"WEB","url":"https://github.com/rabbitmq/rabbitmq-server/releases/tag/v4.3.1"},{"type":"ADVISORY","url":"https://github.com/CVEProject/cvelistV5/tree/main/cves/2026/67xxx/CVE-2026-67240.json"},{"type":"ADVISORY","url":"https://github.com/rabbitmq/rabbitmq-server/security/advisories/GHSA-59c5-553c-57m2"},{"type":"ADVISORY","url":"https://nvd.nist.gov/vuln/detail/CVE-2026-67240"}],"affected":[{"ranges":[{"type":"GIT","repo":"https://github.com/rabbitmq/rabbitmq-server","events":[{"introduced":"95c501fbad76c66156346cf364d158d6e30aa4d9"},{"introduced":"1929eeadf9b2bac12c5434fb56884ef27370580e"},{"fixed":"b15fd2a3e5465cb6ed403d5a774ef61b1a391b89"},{"fixed":"49decca35e59d2cb774e5abd76412cee721308a5"}],"database_specific":{"extracted_events":[{"introduced":"4.2.0"},{"fixed":"4.2.7"},{"introduced":"4.3.0"},{"fixed":"4.3.1"}],"source":["AFFECTED_FIELD","REFERENCES"]}}],"versions":["v4.2.6","v4.3.0","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-2026-67240.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:L/SC:N/SI:N/SA:N"}]}