CVE-2026-45623

PostCSS takes a CSS file and provides an API to analyze and modify its rules by transforming the rules into an Abstract Syntax Tree. In versions 8.5.11 and prior, the PreviousMap parses the / sourceMappingURL=PATH / comment from any CSS string passed to process and dereferences PATH against the...

CVE-2026-45623 PostCSS: Arbitrary file read and information disclosure via attacker-controlled sourceMappingURL in CSS comments

PostCSS takes a CSS file and provides an API to analyze and modify its rules by transforming the rules into an Abstract Syntax Tree. In versions 8.5.11 and prior, the PreviousMap parses the / sourceMappingURL=PATH / comment from any CSS string passed to process and dereferences PATH against the...

CVE-2026-45623

PostCSS takes a CSS file and provides an API to analyze and modify its rules by transforming the rules into an Abstract Syntax Tree. In versions 8.5.11 and prior, the PreviousMap parses the / sourceMappingURL=PATH / comment from any CSS string passed to process and dereferences PATH against the...

CVE-2026-45623 PostCSS: Arbitrary file read and information disclosure via attacker-controlled sourceMappingURL in CSS comments

PostCSS takes a CSS file and provides an API to analyze and modify its rules by transforming the rules into an Abstract Syntax Tree. In versions 8.5.11 and prior, the PreviousMap parses the / sourceMappingURL=PATH / comment from any CSS string passed to process and dereferences PATH against the...

CVE-2026-45623 PostCSS: Arbitrary file read and information disclosure via attacker-controlled sourceMappingURL in CSS comments

PostCSS takes a CSS file and provides an API to analyze and modify its rules by transforming the rules into an Abstract Syntax Tree. In versions 8.5.11 and prior, the PreviousMap parses the / sourceMappingURL=PATH / comment from any CSS string passed to process and dereferences PATH against the...

EUVD-2026-49376

PostCSS takes a CSS file and provides an API to analyze and modify its rules by transforming the rules into an Abstract Syntax Tree. In versions 8.5.11 and prior, the PreviousMap parses the / sourceMappingURL=PATH / comment from any CSS string passed to process and dereferences PATH against the...

CVE-2026-45623

PostCSS vulnerability CVE-2026-45623 affects versions up to 8.5.11. The PreviousMap parses the /*# sourceMappingURL=PATH */ comment from CSS, dereferencing PATH against the local filesystem without scheme, allowlist, or traversal checks. An attacker-controlled CSS input can cause the host process...

CVE-2026-45623: Improper Limitation of a Pathname to a Restricted Directory

PostCSS takes a CSS file and provides an API to analyze and modify its rules by transforming the rules into an Abstract Syntax Tree. In versions 8.5.11 and prior, the PreviousMap parses the / sourceMappingURL=PATH / comment from any CSS string passed to process and dereferences PATH against the...

Directory Traversal

Overview org.webjars.npm:postcss is a PostCSS is a tool for transforming styles with JS plugins. Affected versions of this package are vulnerable to Directory Traversal via the loadMap process. An attacker can access the contents of arbitrary .map files on the filesystem by submitting crafted CSS...

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

Vulnerability Details File: lib/previous-map.js Line: 87-98 loadFile, 129-144 loadMap Root Cause PostCSS auto-detects a / sourceMappingURL=... / comment inside the CSS text it is asked to parse and, unless the caller explicitly passes map: false, attempts to load that path from disk as a "previou...

GHSA-R28C-9Q8G-F849 PostCSS: Path Traversal in Previous Source Map Auto-Loading (sourceMappingURL) leads to Arbitrary .map File Disclosure

Vulnerability Details File: lib/previous-map.js Line: 87-98 loadFile, 129-144 loadMap Root Cause PostCSS auto-detects a / sourceMappingURL=... / comment inside the CSS text it is asked to parse and, unless the caller explicitly passes map: false, attempts to load that path from disk as a "previou...

PT-2026-76686

Name of the Vulnerable Software and Affected Versions PostCSS versions prior to 8.5.18 Description PostCSS transforms CSS files into an Abstract Syntax Tree for analysis and modification. A path traversal issue exists in lib/previous-map.js where the loadMap function passes attacker-controlled...

CVE-2026-45623

creationtimestamp| type| source ---|---|--- 2026-07-23 16:35:02+00:00| published-proof-of-concept| https://github.com/postcss/postcss/security/advisories/GHSA-6g55-p6wh-862q 2026-08-03 18:28:13+00:00| seen| https://bsky.app/profile/cve.skyfleet.blue/post/gp5oyt6frvyqh 2026-08-03 18:31:17+00:00|...

Directory Traversal

Overview postcss is a PostCSS is a tool for transforming styles with JS plugins. Affected versions of this package are vulnerable to Directory Traversal via the process function. An attacker can access arbitrary files and obtain the first 10 bytes of their contents by supplying a crafted...

NPM: PostCSS: Arbitrary file read and information disclosure via attacker-controlled sourceMappingURL in CSS comments

NPM: PostCSS: Arbitrary file read and information disclosure via attacker-controlled sourceMappingURL in CSS comments vulnerability discovered by ? in WordPress Npm postcss versions = 8.5.11...

PostCSS: Arbitrary file read and information disclosure via attacker-controlled sourceMappingURL in CSS comments

Summary PostCSS's PreviousMap parses the / sourceMappingURL=PATH / comment from any CSS string passed to process and dereferences PATH against the local filesystem with no scheme, allowlist, or traversal check. An attacker who controls the CSS input can cause the host process to read any file...

GHSA-6G55-P6WH-862Q PostCSS: Arbitrary file read and information disclosure via attacker-controlled sourceMappingURL in CSS comments

Summary PostCSS's PreviousMap parses the / sourceMappingURL=PATH / comment from any CSS string passed to process and dereferences PATH against the local filesystem with no scheme, allowlist, or traversal check. An attacker who controls the CSS input can cause the host process to read any file...

Directory Traversal

Overview org.webjars.npm:postcss is a PostCSS is a tool for transforming styles with JS plugins. Affected versions of this package are vulnerable to Directory Traversal via the process function. An attacker can access arbitrary files and obtain the first 10 bytes of their contents by supplying a...

PT-2026-64149

Name of the Vulnerable Software and Affected Versions PostCSS versions 8.5.11 and earlier Description PostCSS processes CSS files by transforming them into an Abstract Syntax Tree. The PreviousMap component parses / sourceMappingURL=PATH / comments from CSS strings passed to the process function...

MAL-2026-10687 Malicious code in selparsecss-selector (npm)

--- -= Per source details. Do not edit below this line.=- Source: amazon-inspector f4f8e230628f3622bf88bcd590f98f8065a99ea3e71ef1bf3c330439b7671e1f [email protected] is a name-confusion fork of postcss-selector-parser: package.json declares author 'Ai Pyramid' while the LICENSE-MIT, sour...