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

SummaryBefore tokenizing, selectoriter trims leading/trailing whitespace and comments by running two regexes over the whole raw selector with .search. The trailing one, REWSEND = re.compiler'WSC$', is anchored only at the end $, not the start. Because .search retries the pattern at every offset, ...

PYSEC-2026-4171 Soup Sieve: Polynomial-time ReDoS (O(n²)) in the whitespace/comment trimming regex `RE_WS_END` (triggers on VALID selectors)

Summary Before tokenizing, selectoriter trims leading/trailing whitespace and comments by running two regexes over the whole raw selector with .search. The trailing one, REWSEND = re.compiler'WSC$', is anchored only at the end $, not the start. Because .search retries the pattern at every offset,...

CVE-2026-85999

Soup Sieve is a CSS selector library designed to be used with Beautiful Soup 4. Prior to 2.9, selectoriter in src/soupsieve/cssparser.py trims the raw selector with REWSEND, an end-anchored WSC whitespace-and-comment expression used with search, so the regular expression engine retries a greedy...

AZL-103322 CVE-2026-85999 affecting package python-soupsieve 2.6-3

Soup Sieve is a CSS selector library designed to be used with Beautiful Soup 4. Prior to 2.9, selectoriter in src/soupsieve/cssparser.py trims the raw selector with REWSEND, an end-anchored WSC whitespace-and-comment expression used with search, so the regular expression engine retries a greedy...

UBUNTU-CVE-2026-85999

Soup Sieve is a CSS selector library designed to be used with Beautiful Soup 4. Prior to 2.9, selectoriter in src/soupsieve/cssparser.py trims the raw selector with REWSEND, an end-anchored WSC whitespace-and-comment expression used with search, so the regular expression engine retries a greedy...

CVE-2026-85999

Soup Sieve is a CSS selector library designed to be used with Beautiful Soup 4. Prior to 2.9, selectoriter in src/soupsieve/cssparser.py trims the raw selector with REWSEND, an end-anchored WSC whitespace-and-comment expression used with search, so the regular expression engine retries a greedy...

CVE-2026-85999: Uncontrolled Resource Consumption

Soup Sieve is a CSS selector library designed to be used with Beautiful Soup 4. Prior to 2.9, selectoriter in src/soupsieve/cssparser.py trims the raw selector with REWSEND, an end-anchored WSC whitespace-and-comment expression used with search, so the regular expression engine retries a greedy...