CVE-2026-73646

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.

CVSS v3 7.5 HIGH

7.5^/10

CVSS v3 : HIGH

Vector :

Exploitability : 3.9 / Impact : 3.6

Attack Vector NETWORK

Attack Complexity LOW

Privileges Required NONE

User Interaction NONE

Confidentiality Impact HIGH

Integrity Impact NONE

Availability Impact NONE

Scope UNCHANGED

References

Link	Resource
https://github.com/postcss/postcss/commit/95663d3eb7ba26f4854dd19d3b4f4425760cf56c
https://github.com/postcss/postcss/releases/tag/8.5.18
https://github.com/postcss/postcss/security/advisories/GHSA-r28c-9q8g-f849
https://github.com/postcss/postcss/security/advisories/GHSA-r28c-9q8g-f849

Configurations

No configuration.

History

No history.

Information

Published : 2026-08-17 16:17

Updated : 2026-08-17 17:16

NVD link : CVE-2026-73646

Mitre link : CVE-2026-73646

CVE.ORG link : CVE-2026-73646

JSON object : View

Products Affected

No product.

CWE

CWE-22

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

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