CVE-2026-49476

Soup Sieve (the CSS selector engine used by Beautiful Soup 4) is vulnerable prior to version 2.8.4 due to an unbounded memory allocation when compiling large comma‑separated selector lists. An attacker can supply a crafted selector string to soupsieve.compile() or to BeautifulSoup’s .select()/.se...

CVE-2026-49477

Soup Sieve (CSS selector engine used by Beautiful Soup 4) Before 2.8.4 contains a regular-expression backtracking bug in soupsieve/css_parser.py (VALUE pattern) that enables catastrophic backtracking on unterminated quoted attribute values, causing CPU exhaustion and potential DoS when compiling ...