Description
An issue was discovered in PostCSS before 8.4.31. The vulnerability affects linters using PostCSS to parse external untrusted CSS. An attacker can prepare CSS in such a way that it will contains parts parsed by PostCSS as a CSS comment. After processing by PostCSS, it will be included in the PostCSS output in CSS nodes (rules, properties) despite being included in a comment.
References (5)
Core 5
Core References
Issue Tracking
https://github.com/github/advisory-database/issues/2820
Patch, Release Notes
https://github.com/postcss/postcss/releases/tag/8.4.31
Scores
CVSS v3
5.3
EPSS
0.0022
EPSS Percentile
44.3%
Attack Vector
NETWORK
CVSS:3.1/AV:N/AC:L/PR:N/UI:N/S:U/C:N/I:L/A:N
CISA SSVC
Vulnrichment
Exploitation
none
Automatable
yes
Technical Impact
partial
Details
CWE
CWE-74
Status
published
Products (2)
npm/postcss
0 - 8.4.31npm
postcss/postcss
< 8.4.31
Published
Sep 29, 2023
Tracked Since
Feb 18, 2026