High 7.5Published Aug 17, 2026

CVE-2026-73646PostCSS: Path Traversal in Previous Source Map Auto-Loading (sourceMappingURL) leads to Arbitrary .map File Disclosure

Updated under an hour ago (2026-10-19 06:10 UTC)

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It affects postcss. Add what you run to find out whether that includes you.

No exploitation reported and no EPSS estimate yet.

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Every CVE for postcss

Exploited in the last 30 days

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: 7.5 HIGH (v3.1, CNA)CVSS:3.1/AV:N/AC:L/PR:N/UI:N/S:U/C:H/I:N/A:N
Weakness (CWE): CWE-22
Known exploited: Not in CISA's KEV catalog
EPSS (exploitation in the next 30 days): Not loaded for this CVE
Assigned by: GitHub_M
NVD analysis: Awaiting Analysis
Record last updated: Aug 17, 2026
First seen by InfoSec Signals: Oct 9, 2026

Affected products

Affected products

postcss postcss postcss:postcss (from the name)	before 8.5.18	CNA record

References

https://github.com/postcss/postcss/security/advisories/GHSA-r28c-9q8g-f849x-refsource-confirm
https://github.com/postcss/postcss/commit/95663d3eb7ba26f4854dd19d3b4f4425760cf56cx-refsource-misc
https://github.com/postcss/postcss/releases/tag/8.5.18x-refsource-misc

The CVE record on cve.org NVD's entry

The CVE record is authoritative. Products marked “from the name” were identified from the CNA's free-text names, not a CPE, and are matched less certainly. This product uses the NVD API but is not endorsed or certified by the NVD.