A vulnerability was determined in postcss-selector-parser up to 6.1.2/7.1.2. Affected is the function toString of the file src/selectors/container.js of the component AST Serialization. Executing a manipulation can lead to uncontrolled recursion. It is possible to launch the attack remotely. The exploit has been publicly disclosed and may be utilized. Upgrading to version 6.1.3 and 7.1.3 is able to address this issue. This patch is called 5bc698cef66f8abd12610dc623e5d67cbc0f869d. It is suggested to upgrade the affected component. The vendor explains, that according to his definition DoS on server-side on user-generated CSS is low risk for us (since most users compile own CSS with PostCSS). The commits were backported to 6.x branch, which was the most downloaded version.
Weakness
The product does not release or incorrectly releases a resource before it is made available for re-use.
Potential Mitigations
- Use a language that does not allow this weakness to occur or provides constructs that make this weakness easier to avoid.
- For example, languages such as Java, Ruby, and Lisp perform automatic garbage collection that releases memory for objects that have been deallocated.
Related Attack Patterns
- https://cwe.mitre.org/data/definitions/125.html
- https://cwe.mitre.org/data/definitions/130.html
- https://cwe.mitre.org/data/definitions/131.html
- https://cwe.mitre.org/data/definitions/494.html
- https://cwe.mitre.org/data/definitions/495.html
- https://cwe.mitre.org/data/definitions/496.html
- https://cwe.mitre.org/data/definitions/666.html
References
- https://gist.github.com/bx33661/581e3a38134601c04e19b4dfc9b459b9
- https://github.com/postcss/postcss-selector-parser/commit/5bc698cef66f8abd12610dc623e5d67cbc0f869d
- https://github.com/postcss/postcss-selector-parser/releases/tag/7.1.3
- https://vuldb.com/cve/CVE-2026-9358
- https://vuldb.com/submit/813080
- https://vuldb.com/vuln/365321
- https://vuldb.com/vuln/365321/cti