Vulnerability record · CVE-2026-49476 · published 14 July 2026
CVE-2026-49476: Facelessuser soup sieve uncontrolled resource consumption vulnerability
FFacelessuser · Soup Sieve
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.
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:3.1/AV:N/AC:L/PR:N/UI:N/S:U/C:N/I:N/A:H
Affected products
1 vulnerable configurations from NVD's CPE data, grouped by vendor and product.
References
| Link | Tags |
|---|---|
| https://github.com/facelessuser/soupsieve/commit/28108ab805818c832d9568142a99844fd95a0d39 | Patch |
| https://github.com/facelessuser/soupsieve/releases/tag/2.8.4 | Release Notes |
| https://github.com/facelessuser/soupsieve/security/advisories/GHSA-2wc2-fm75-p42x | ExploitVendor Advisory |
| https://github.com/facelessuser/soupsieve/security/advisories/GHSA-2wc2-fm75-p42x | ExploitVendor Advisory |
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Related vulnerabilities
Same products first, then exploited flaws of the same weakness class.
Source: NIST National Vulnerability Database (record CVE-2026-49476), CISA KEV, FIRST EPSS (scores of 2026-09-28). This page is refreshed as NVD updates the record.