{"affected":[{"product":"soupsieve","source":"CNA: GitHub_M","vendor":"facelessuser","versions":[{"status":"affected","version":"< 3.0"}]}],"cveId":"CVE-2026-126191","cwes":["CWE-1333"],"description":"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.","epss":null,"exploits":[],"kev":null,"metrics":[{"score":7.5,"severity":"high","source":"CNA: GitHub_M","vector":"CVSS:3.1/AV:N/AC:L/PR:N/UI:N/S:U/C:N/I:N/A:H","version":"3.1"},{"score":7.5,"severity":"high","source":"NVD: security-advisories@github.com","vector":"CVSS:3.1/AV:N/AC:L/PR:N/UI:N/S:U/C:N/I:N/A:H","version":"3.1"}],"modifiedAt":1794503852627,"publishedAt":1794502621566,"references":[{"source":"CNA: GitHub_M","tags":["x_refsource_CONFIRM"],"url":"https://github.com/facelessuser/soupsieve/security/advisories/GHSA-6655-6qjp-jx7x"},{"source":"CNA: GitHub_M","tags":["x_refsource_MISC"],"url":"https://github.com/facelessuser/soupsieve/pull/300"},{"source":"CNA: GitHub_M","tags":["x_refsource_MISC"],"url":"https://github.com/facelessuser/soupsieve/commit/dbfa2854ff31a863326bd6660d4e55c6f068db9e"},{"source":"CNA: GitHub_M","tags":["x_refsource_MISC"],"url":"https://github.com/facelessuser/soupsieve/releases/tag/3.0"},{"source":"security-advisories@github.com","tags":[],"url":"https://github.com/facelessuser/soupsieve/commit/dbfa2854ff31a863326bd6660d4e55c6f068db9e"},{"source":"security-advisories@github.com","tags":[],"url":"https://github.com/facelessuser/soupsieve/pull/300"},{"source":"security-advisories@github.com","tags":[],"url":"https://github.com/facelessuser/soupsieve/releases/tag/3.0"},{"source":"security-advisories@github.com","tags":[],"url":"https://github.com/facelessuser/soupsieve/security/advisories/GHSA-6655-6qjp-jx7x"}],"remediation":[],"revision":"19a861ed0c7551309e7b8073504270eb30ef4f3b1dfd0d70d2746b3f9a78862e","sources":[{"modifiedAt":1794502621566,"name":"CNA: GitHub_M","retrievedAt":1794503375639,"url":"https://www.cve.org/CVERecord?id=CVE-2026-126191"},{"modifiedAt":1794503852627,"name":"NVD","retrievedAt":1794507523875,"url":"https://nvd.nist.gov/vuln/detail/CVE-2026-126191"}],"ssvc":null,"status":"published","title":"Soup Sieve: Exponential ReDoS in selector compilation via \\9-run in CSS_ESCAPES/IDENTIFIER","updatedAt":1794507523875}