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CVE-2026-69153GHSA-FXQJ-RQCC-2CMP

PostCSS: incomplete fix of CVE-2026-45623 — attacker-controlled sourceMappingURL reads arbitrary .map files when `from` is unset

Published
Last modified
published
Not listed in CISA KEV
Fix
Fixed in 8.5.19, 8.5.23
None on Exploit-DB, Metasploit or GitHub
  • Exploitation: poc
  • Automatable: no
  • Technical impact: partial

Summary

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 8.5.19, if from is unset, an attacker can cause PreviousMap.loadFile() to read an unintended source-map file by supplying an absolute or directory-traversal sourceMappingURL. The resulting map’s sources and sourcesContent may then be exposed to the application. This issue is fixed in version 8.5.19.

Timeline

  1. CVE published
  2. CISA SSVC assessment

    Exploitation: poc · Automatable: no · Technical impact: partial

  3. Record last updated

Affected versions

  • postcss postcss

    fixed in 8.5.19

  • postcssnpm

    fixed in 8.5.23

References 3

GitHub · postcss/postcss