CVE-2026-73646

Published: Aug 17, 2026Modified: Sep 18, 2026

7.5

Vector

CVSS:3.1/AV:N/AC:L/PR:N/UI:N/S:U/C:H/I:N/A:N

Exploitability: 3.9 / Impact: 3.6

Source: security-advisories@github.com (Secondary)

Description

PostCSS takes a CSS file and provides an API to analyze and modify its rules by transforming the rules into an Abstract Syntax Tree. Prior to 8.5.18, lib/previous-map.js loadMap() passes attacker-controlled sourceMappingURL values to join(dirname(opts.from), annotation), and loadFile() permits traversed or absolute .map paths, allowing untrusted CSS processed without map: false to disclose sourcesContent from arbitrary reachable .map files through result.map. This issue is fixed in version 8.5.18.

Related CWEs

CWE-22

Improper Limitation of a Pathname to a Restricted Directory ('Path Traversal')

The product uses external input to construct a pathname that is intended to identify a file or directory that is located underneath a restricted parent directory, but the product does not properly neutralize special elements within the pathname that can cause the pathname to resolve to a location that is outside of the restricted directory.

References (4)

https://github.com/postcss/postcss/commit/95663d3eb7ba26f4854dd19d3b4f4425760cf56c

Source: security-advisories@github.com

https://github.com/postcss/postcss/releases/tag/8.5.18

Source: security-advisories@github.com

https://github.com/postcss/postcss/security/advisories/GHSA-r28c-9q8g-f849

Source: security-advisories@github.com

https://github.com/postcss/postcss/security/advisories/GHSA-r28c-9q8g-f849

Source: 134c704f-9b21-4f2e-91b3-4a467353bcc0

Timeline

No history available yet.