Vulnerability 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 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.
CVSS Score
HIGH
Affected Products
| Vendor | Product | Versions |
|---|---|---|
| Facelessuser | Soup Sieve | < 2.8.4 |
Related Weaknesses (CWE)
References
- https://github.com/facelessuser/soupsieve/commit/28108ab805818c832d9568142a99844Patch
- https://github.com/facelessuser/soupsieve/releases/tag/2.8.4Release Notes
- https://github.com/facelessuser/soupsieve/security/advisories/GHSA-2wc2-fm75-p42ExploitVendor Advisory
- https://github.com/facelessuser/soupsieve/security/advisories/GHSA-2wc2-fm75-p42ExploitVendor Advisory
FAQ
What is CVE-2026-49476?
CVE-2026-49476 is a vulnerability with a CVSS score of 7.5 (HIGH). 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 sel...
How severe is CVE-2026-49476?
CVE-2026-49476 has been rated HIGH with a CVSS base score of 7.5/10. Review the CVSS metrics above for detailed severity breakdown.
Is there a patch for CVE-2026-49476?
Check the references section above for vendor advisories and patch information. Affected products include: Facelessuser Soup Sieve.