{"id":"CVE-2026-126191","summary":"Soup Sieve: Exponential ReDoS in selector compilation via \\9-run in CSS_ESCAPES/IDENTIFIER","details":"Soup Sieve is a CSS selector library designed to be used with Beautiful Soup 4. Prior to 3.0, the CSS_ESCAPES and IDENTIFIER regular-expression subpatterns can backtrack exponentially on runs of ambiguous digit escapes in an attribute-name or tag position of an otherwise valid selector. The failure occurs during selector compilation through soupsieve.compile() or Beautiful Soup select() before SELECTOR_LIMIT is applied, so an application that accepts untrusted selector strings can have a worker stalled by a short input. This issue is fixed in version 3.0.","aliases":["GHSA-6655-6qjp-jx7x"],"modified":"2026-11-13T02:47:25.516669720Z","published":"2026-11-12T16:57:01.566Z","database_specific":{"cna_assigner":"GitHub_M","cwe_ids":["CWE-1333"],"osv_generated_from":"https://github.com/CVEProject/cvelistV5/tree/main/cves/2026/126xxx/CVE-2026-126191.json"},"references":[{"type":"ADVISORY","url":"https://github.com/CVEProject/cvelistV5/tree/main/cves/2026/126xxx/CVE-2026-126191.json"},{"type":"FIX","url":"https://github.com/facelessuser/soupsieve/commit/dbfa2854ff31a863326bd6660d4e55c6f068db9e"},{"type":"FIX","url":"https://github.com/facelessuser/soupsieve/pull/300"},{"type":"WEB","url":"https://github.com/facelessuser/soupsieve/releases/tag/3.0"},{"type":"ADVISORY","url":"https://github.com/facelessuser/soupsieve/security/advisories/GHSA-6655-6qjp-jx7x"},{"type":"ADVISORY","url":"https://nvd.nist.gov/vuln/detail/CVE-2026-126191"}],"affected":[{"ranges":[{"type":"GIT","repo":"https://github.com/facelessuser/soupsieve","events":[{"introduced":"0"},{"fixed":"e39e4e7fa57d693da8d1f2422a7c9a9c7a6d5cc7"},{"fixed":"dbfa2854ff31a863326bd6660d4e55c6f068db9e"}],"database_specific":{"extracted_events":[{"strategy":"StringRangeExpression","range":[{"introduced":"0"},{"fixed":"3.0"}],"source":"AFFECTED_FIELD"},{"range":[{"fixed":"dbfa2854ff31a863326bd6660d4e55c6f068db9e"}],"source":"REFERENCES_COMMIT"},{"range":[{"fixed":"e39e4e7fa57d693da8d1f2422a7c9a9c7a6d5cc7"}],"source":"REFERENCES_TAG","original_tag":"3.0"}]}}],"versions":["2.10","2.9.2","2.9.1","2.9","2.8.4","2.8.3","2.8.2","2.8.1","2.8","2.7","2.6","2.5","2.4.1","2.4","2.3.2.post1","2.3.2","2.3.1","2.3","2.2.1","2.2","2.1.0","2.0.1","2.0.0","1.9.4","1.9.3","1.9.2","1.9.1","1.9.0","1.8.0","1.7.3","1.7.2","1.7.1","1.7.0","1.6.1","1.6.0","1.5.0","1.4.0","1.3.1","1.3.0","1.2.1","1.2.0","1.1.0","1.0.2","1.0.1","1.0.0","1.0.0b2","1.0.0b1","0.6.0","0.5.3","0.5.2","0.5.1","0.5.0","0.4.0"],"database_specific":{"source":"https://storage.googleapis.com/cve-osv-conversion/osv-output/CVE-2026-126191.json"}}],"schema_version":"1.9.2","severity":[{"type":"CVSS_V3","score":"CVSS:3.1/AV:N/AC:L/PR:N/UI:N/S:U/C:N/I:N/A:H"}]}