CVE-2026-45623

Published: Lug 27, 2026 Last Modified: Lug 27, 2026
ExploitDB:
Other exploit source:
Google Dorks:
HIGH 7,5
Source: [email protected]
Attack Vector: network
Attack Complexity: low
Privileges Required: none
User Interaction: none
Scope: unchanged
Confidentiality: high
Integrity: none
Availability: none

Description

AI Translation Available

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 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 readable by Node and leak the first ~10 bytes of its content through the resulting JSON.parse SyntaxError message. The bug also yields a precise file-existence oracle and a controllable-read primitive that may be combined with large-file targets for DoS. The behaviour is triggered with PostCSS's default options — no from, no map, no plugins required — and is therefore reachable from any pipeline that runs untrusted CSS through PostCSS (CMS themes, user-uploaded styles, browser-extension/userstyle processors, build pipelines for third-party packages, blog comment renderers, etc.). This issue has been fixed in version 8.5.12.

22

Improper Limitation of a Pathname to a Restricted Directory ('Path Traversal')

Stable
Abstraction: Base Structure: Simple
Common Consequences
Security Scopes Affected:
Integrity Confidentiality Availability
Potential Impacts:
Execute Unauthorized Code Or Commands Modify Files Or Directories Read Files Or Directories Dos: Crash, Exit, Or Restart
Applicable Platforms
Technologies: AI/ML
Likelihood of Exploit: High
View CWE Details
200

Exposure of Sensitive Information to an Unauthorized Actor

Draft
Abstraction: Class Structure: Simple
Common Consequences
Security Scopes Affected:
Confidentiality
Potential Impacts:
Read Application Data
Applicable Platforms
Technologies: Not Technology-Specific, Web Based, Mobile
Likelihood of Exploit: High
View CWE Details
https://github.com/postcss/postcss/security/advisories/GHSA…
https://github.com/postcss/postcss/security/advisories/GHSA-6g55-p6wh-862q
https://github.com/postcss/postcss/security/advisories/GHSA…
https://github.com/postcss/postcss/security/advisories/GHSA-6g55-p6wh-862q