PostCSS: incomplete fix of GHSA-6g55-p6wh-862q — attacker-controlled sourceMappingURL reads arbitrary .map files when `from` is unset

Summary The fix for GHSA-6g55-p6wh-862q added a guard in lib/previous-map.js PreviousMap.loadFile that restricts an attacker-controlled sourceMappingURL from a CSS comment to a .map extension and, for untrusted maps, rejects .. traversal and absolute paths. The traversal/absolute rejection is...

GHSA-FXQJ-RQCC-2CMP PostCSS: incomplete fix of GHSA-6g55-p6wh-862q — attacker-controlled sourceMappingURL reads arbitrary .map files when `from` is unset

Summary The fix for GHSA-6g55-p6wh-862q added a guard in lib/previous-map.js PreviousMap.loadFile that restricts an attacker-controlled sourceMappingURL from a CSS comment to a .map extension and, for untrusted maps, rejects .. traversal and absolute paths. The traversal/absolute rejection is...

NPM: PostCSS: incomplete fix of GHSA-6g55-p6wh-862q — attacker-controlled sourceMappingURL reads arbitrary .map files when `from` is unset

NPM: PostCSS: incomplete fix of GHSA-6g55-p6wh-862q — attacker-controlled sourceMappingURL reads arbitrary .map files when from is unset vulnerability discovered by ? in WordPress Npm postcss versions = 8.5.22...

EUVD-2026-52373

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...

CVE-2026-69153

CVE-2026-69153 (PostCSS) affects PostCSS prior to 8.5.19. If the option from is unset, an attacker can cause PreviousMap.loadFile() to read an unintended source-map file by supplying an absolute or directory-traversal sourceMappingURL, exposing the map’s sources and sourcesContent. The issue is f...

CVE-2026-69153 PostCSS: incomplete fix of CVE-2026-45623 — attacker-controlled sourceMappingURL reads arbitrary .map files when `from` is unset

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...