{"cve":"CVE-2026-49477","nvd":{"published":"2026-07-14T21:17:02.007","modified":"2026-10-24T21:10:00.130","status":"Analyzed","description":"Soup Sieve is a CSS selector library designed to be used with Beautiful Soup 4. Prior to 2.8.4, the CSS selector parser in soupsieve contains a regular expression vulnerable to catastrophic backtracking when processing an attribute selector with an unterminated quoted value in soupsieve/css_parser.py, allowing an attacker who can supply untrusted CSS selector strings to soupsieve.compile() or Beautiful Soup .select() / .select_one() to cause CPU exhaustion and denial of service. This issue is fixed in version 2.8.4.","cvss_v4":null,"cvss_v3":{"version":"3.1","vector":"CVSS:3.1/AV:N/AC:L/PR:N/UI:N/S:U/C:N/I:N/A:H","score":7.5},"cwes":["CWE-400","CWE-1333"],"references":["https://github.com/facelessuser/soupsieve/commit/eb4397618709186c109400448c6043b728217dc3","https://github.com/facelessuser/soupsieve/releases/tag/2.8.4","https://github.com/facelessuser/soupsieve/security/advisories/GHSA-836r-79rf-4m37","https://github.com/facelessuser/soupsieve/security/advisories/GHSA-836r-79rf-4m37"],"products":["facelessuser:soup_sieve"],"source":"nvd","synced_at":"2026-10-25T17:50:06.907763985+00:00"},"epss":{"cve":"CVE-2026-49477","score":0.00644,"percentile":0.50572,"date":"2026-10-25"},"kev":null,"osv":[{"id":"GHSA-836r-79rf-4m37","url":"https://osv.dev/vulnerability/GHSA-836r-79rf-4m37","summary":"Soup Sieve: Regular Expression Denial of Service (ReDoS) via Selector Parser","modified":"2026-09-10T03:51:10.949295830Z","packages":[{"ecosystem":"PyPI","name":"soupsieve","purl":"pkg:pypi/soupsieve","ranges":["<2.8.4"],"fixed":["2.8.4"]}]},{"id":"PYSEC-2026-3072","url":"https://osv.dev/vulnerability/PYSEC-2026-3072","summary":"Soup Sieve: Regular Expression Denial of Service (ReDoS) via Selector Parser","modified":"2026-07-13T16:31:33.705856864Z","packages":[{"ecosystem":"PyPI","name":"soupsieve","purl":"pkg:pypi/soupsieve","ranges":["<2.8.4"],"fixed":["2.8.4"]}]}],"attribution":["This product uses the NVD API but is not endorsed or certified by the NVD.","EPSS scores: FIRST Exploit Prediction Scoring System, https://www.first.org/epss","Known exploited vulnerabilities: CISA Known Exploited Vulnerabilities Catalog, https://www.cisa.gov/known-exploited-vulnerabilities-catalog","Package advisories: OSV (https://osv.dev), from the GitHub Advisory Database, PyPA, Go, RustSec and other ecosystem databases, under CC-BY 4.0 or CC0","CVE records: the CVE Program's CVE List (https://www.cve.org), under its terms of use (https://www.cve.org/Legal/TermsOfUse). CVE is a registered trademark of The MITRE Corporation; this product is not affiliated with the CVE Program."]}