CVE-2026-9358
postcss-selector-parser AST Serialization container.js toString recursion
- State
- Published
- Severity
- 5.3 Medium
- Published
- May 24, 2026
- Updated
- Jun 15, 2026
- Reserved
- May 23, 2026
Description
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.
Scores
| CVSS | Score | Vector | Source |
|---|---|---|---|
| 4.0 | 5.3 Medium | CVSS:4.0/AV:N/AC:L/AT:N/PR:N/UI:P/VC:N/VI:N/VA:L/SC:N/SI:N/SA:N/E:P | VulDB |
| 3.1 | 4.3 Medium | CVSS:3.1/AV:N/AC:L/PR:N/UI:R/S:U/C:N/I:N/A:L/E:P/RL:O/RC:C | VulDB |
| 3.0 | 4.3 Medium | CVSS:3.0/AV:N/AC:L/PR:N/UI:R/S:U/C:N/I:N/A:L/E:P/RL:O/RC:C | VulDB |
| 2.0 | 5.0 Medium | AV:N/AC:L/Au:N/C:N/I:N/A:P/E:POC/RL:OF/RC:C | VulDB |
Weaknesses
Affected Products
| Product | Versions |
|---|---|
postcss-selector-parsern/a |
|
References
- VDB-365321 | postcss-selector-parser AST Serialization container.js toString recursionvdb-entrytechnical-description
- VDB-365321 | CTI Indicators (IOB, IOC, TTP, IOA)signaturepermissions-required
- CVE-2026-9358 | CVE Analysis and Reportthird-party-advisory
- Submit #813080 | postcss-selector-parser postcss <= 7.1.1 CWE-674: Uncontrolled Recursionthird-party-advisory
- https://gist.github.com/bx33661/581e3a38134601c04e19b4dfc9b459b9exploit
- https://github.com/postcss/postcss-selector-parser/commit/5bc698cef66f8abd12610dc623e5d67cbc0f869dpatch
- https://github.com/postcss/postcss-selector-parser/releases/tag/7.1.3patch
Every record here comes from the CVE Program’s CVE List. © 1999–2026 The MITRE Corporation. CVE is a registered trademark of The MITRE Corporation. The records are reproduced under the CVE Program terms of use.