CVE-2026-49476

HIGH

Soup Sieve: Memory Exhaustion via Large Comma-Separated Selector Lists in soupsieve

Title source: cna
STIX 2.1

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.

References (3)

Core 3

Scores

CVSS v3 7.5
EPSS 0.0060
EPSS Percentile 44.8%
Attack Vector NETWORK
CVSS:3.1/AV:N/AC:L/PR:N/UI:N/S:U/C:N/I:N/A:H

CISA SSVC

Vulnrichment
Exploitation poc
Automatable yes
Technical Impact partial

Details

CWE
CWE-400 CWE-770
Status published
Products (1)
facelessuser/soupsieve < 2.8.4
Published Jul 14, 2026
Tracked Since Jul 15, 2026