CVE-2026-73646highCWE-22

CVE-2026-73646: high-severity vulnerability in postcss

PostCSS: Path Traversal in Previous Source Map Auto-Loading (sourceMappingURL) leads to Arbitrary .map File Disclosure

Published

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21Vexday Risk Score

No sign of exploitation. No public exploitation artifact known so far.

ssvc Trackcvss 7.5epss 0.5%
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:3.1/AV:N/AC:L/PR:N/UI:N/S:U/C:H/I:N/A:N
Affected products
postcss · postcss
Related CVEs — postcss

In the same product, most dangerous first.

CVE-2026-45623HIGHPostCSS: Arbitrary file read and information disclosure via attacker-controlled sourceMappingURL in CSS commentsEPSS 0.6%CVE-2026-69153MEDIUMPostCSS: incomplete fix of CVE-2026-45623 — attacker-controlled sourceMappingURL reads arbitrary .map files when `from` is unsetEPSS 0.5%CVE-2026-41305MEDIUMPostCSS has XSS via Unescaped </style> in its CSS Stringify OutputEPSS 0.2%