PostCSS: Arbitrary file read and information disclosure via attacker-controlled sourceMappingURL in CSS comments
High-risk advisory
CVE-2026-45623
Summary
PostCSS: Arbitrary file read and information disclosure via attacker-controlled sourceMappingURL in CSS comments
Why it matters
GitHub has published a reviewed security advisory for postcss. Prioritize it with other application dependency updates.
Operator check
Check whether postcss is present in application dependency manifests, lockfiles, or build images. Review the GitHub advisory and upgrade to a patched version where available.
Sources
PatchBrief uses public sources. It does not scan environments, verify exposure, or replace vendor guidance.