PyPI/soupsieve CVE-2026-85999: medium 5.3, EPSS 0.61%

Soup Sieve: Polynomial-time ReDoS (O(n²)) in the whitespace/comment trimming regex `RE_WS_END` (triggers on VALID selectors)

Action: Upgrade soupsieve to 2.9.0 or later.

pip install soupsieve==2.9.0

Affected

Fixed versions

Sources

• osv: PYSEC-2026-4171
• https://github.com/facelessuser/soupsieve/security/advisories/GHSA-j934-xhv5-fg8f
• https://nvd.nist.gov/vuln/detail/CVE-2026-85999
• https://github.com/facelessuser/soupsieve/commit/cf198fcddc9230f06ed39f974eba0ce076b85cda
• https://github.com/facelessuser/soupsieve
• https://github.com/facelessuser/soupsieve/releases/tag/2.9
• https://pypi.org/project/soupsieve
• https://github.com/advisories/GHSA-j934-xhv5-fg8f

CVE-2026-85999 · published 2026-10-01T16:38:33.150066Z · modified 2026-10-01T17:45:16.845996024Z · JSON