CVE-2026-49476

HIGH
MEDIUM Priority: 0.05 BB Relevance: 75/100
Published: 2026-07-14 Modified: 2026-10-24 First seen: 2026-10-29 Status: active

Attack Surface

Network Low Complexity No Auth No Interaction

CVSS Vector Breakdown

AV: Network
AC: Low
PR: None
UI: None
S: Unchanged
C: None
I: None
A: High

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.

Weakness Classification (2)

Affected Software (1)

VendorProductVersion
facelessuser soup_sieve < 2.8.4

Bug Bounty Relevance

75 / 100
✓ Network accessible
✓ No authentication
✓ Low complexity
✓ No user interaction

CVSS Score

7.5 / 10.0 v3.1
CVSS:3.1/AV:N/AC:L/PR:N/UI:N/S:U/C:N/I:N/A:H

EPSS — Exploitation Probability

0.64%
Raw Score 0.006440
Percentile 50.8%
Date 2026-10-29

EPSS Trend

2026-10-29
0.00644
2026-10-28
0.00644

Intelligence Sources

nvd ref →