CVE-2026-49476
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 allocates unbounded memory when compiling large comma-separated selector lists, allowing an attacker who can supply a crafted selector string to soupsieve.compile() or Beautiful Soup .select() / .select_one() to allocate hundreds of megabytes of heap memory from a relatively small input and cause denial of service. This issue is fixed in version 2.8.4.
Weakness
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 allocates unbounded memory when compiling large comma-separated selector lists, allowing an attacker who can supply a crafted selector string to soupsieve.compile() or Beautiful Soup .select() / .select_one() to allocate hundreds of megabytes of heap memory from a relatively small input and cause denial of service. This issue is fixed in version 2.8.4.
Affected products
- facelessuser soup_sieve
References
- https://github.com/facelessuser/soupsieve/commit/28108ab805818c832d9568142a99844fd95a0d39
- https://github.com/facelessuser/soupsieve/releases/tag/2.8.4
- https://github.com/facelessuser/soupsieve/security/advisories/GHSA-2wc2-fm75-p42x
- https://github.com/facelessuser/soupsieve/security/advisories/GHSA-2wc2-fm75-p42x
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