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CVE-2026-73646

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

This page contains facts from public vulnerability sources. Check the original advisory before updating.

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 · EPSS 0.5% · Fix available

Published
Updated

Stack: system · node

Affected products and versions

  • postcss

    Versions
    • < 8.5.18: Affected

    No fix published

  • node-postcss Debian:12

    Versions
    • 8.4.20+~cs8.0.23-1
    • 8.4.20+~cs8.0.23-1+deb12u1
    • 8.4.31+~cs8.0.26-1
    • 8.4.39+~cs9.2.29-1
    • 8.4.49+~cs9.2.32-1
    • 8.5.12+~cs9.3.32-1
    • 8.5.14+~cs9.3.34-1
    • 8.5.15+~cs9.3.34-1
    • 8.5.15+~cs9.3.38-1
    • 8.5.15+~cs9.3.39-1
    • 8.5.19+~cs10.2.23-1
    • 8.5.21+~cs10.2.23-1
    • 8.5.23+~cs10.2.23-1
    • 8.5.25+~cs10.2.23-1
    • 8.5.26+~cs10.2.24-1
    • 8.5.28+~cs10.2.24-1
    • 8.5.6+~cs9.3.28-1
    • 8.5.8+~cs9.3.30-1
    • 8.5.9+~cs9.3.30-1
    Affected ranges
    • ECOSYSTEM: (−∞, +∞)

    No fix published

  • node-postcss Debian:13

    Versions
    • 8.4.49+~cs9.2.32-1
    • 8.5.12+~cs9.3.32-1
    • 8.5.14+~cs9.3.34-1
    • 8.5.15+~cs9.3.34-1
    • 8.5.15+~cs9.3.38-1
    • 8.5.15+~cs9.3.39-1
    • 8.5.19+~cs10.2.23-1
    • 8.5.21+~cs10.2.23-1
    • 8.5.23+~cs10.2.23-1
    • 8.5.25+~cs10.2.23-1
    • 8.5.26+~cs10.2.24-1
    • 8.5.28+~cs10.2.24-1
    • 8.5.6+~cs9.3.28-1
    • 8.5.8+~cs9.3.30-1
    • 8.5.9+~cs9.3.30-1
    Affected ranges
    • ECOSYSTEM: (−∞, +∞)

    No fix published

  • node-postcss Debian:14

    Versions
    • 8.4.49+~cs9.2.32-1
    • 8.5.12+~cs9.3.32-1
    • 8.5.14+~cs9.3.34-1
    • 8.5.15+~cs9.3.34-1
    • 8.5.15+~cs9.3.38-1
    • 8.5.15+~cs9.3.39-1
    • 8.5.6+~cs9.3.28-1
    • 8.5.8+~cs9.3.30-1
    • 8.5.9+~cs9.3.30-1
    Affected ranges
    • ECOSYSTEM: < 8.5.19+~cs10.2.23-1

    Update to 8.5.19+~cs10.2.23-1

  • postcss npm

    Affected ranges
    • SEMVER: < 8.5.18

    Update to 8.5.18

  • node-postcss Ubuntu:20.04:LTS

    Versions
    • 6.0.23-1
    • 6.0.23-3
    Affected ranges
    • ECOSYSTEM: (−∞, +∞)

    No fix published

  • node-postcss Ubuntu:22.04:LTS

    Versions
    • 8.2.1+~cs5.3.23-8
    • 8.4.5+~cs7.1.51-2
    • 8.4.6+~cs7.3.21-1
    Affected ranges
    • ECOSYSTEM: (−∞, +∞)

    No fix published

  • node-postcss Ubuntu:24.04:LTS

    Versions
    • 8.4.20+~cs8.0.23-1
    • 8.4.31+~cs8.0.26-1
    Affected ranges
    • ECOSYSTEM: (−∞, +∞)

    No fix published

  • node-postcss Ubuntu:26.04:LTS

    Versions
    • 8.5.6+~cs9.3.28-1
    • 8.5.8+~cs9.3.30-1
    Affected ranges
    • ECOSYSTEM: (−∞, +∞)

    No fix published

Original sources

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