- 5.3MediumCVSS base score
- 0.33%Exploitation in 30 daysEPSS · top 74% of all CVEs
- NoKnown exploitednot in CISA's KEV catalog
- YesPublic exploitsa reference or SSVC says so
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.
Public exploit
An exploit or proof of concept is public: anyone can try it against an unpatched system. A reference of the record is tagged as an exploit. CISA's SSVC rates its exploitation: a proof of concept is public.
Show the exploits1
References tagged exploit1 reference
Timeline
ID reserved
By VulDB
- 1 day later
· 1 day later
Published
- 22 days later
· 22 days later
Record updated
Changes after publication (a new score, a public exploit, EPSS crossing 1, 10 or 50 %, leaving KEV) are kept since November 2026; earlier ones are not known.
Scores
| Scored by | CVSS | Score | Vector |
|---|---|---|---|
| VulDBCNA (assigner) | 4.0 | Medium5.3 | 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 |
| VulDBCNA (assigner) | 3.1 | Medium4.3 | 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 |
| VulDBCNA (assigner) | 3.0 | Medium4.3 | 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 |
| VulDBCNA (assigner) | 2.0 | Medium5.0 | AV:N/AC:L/Au:N/C:N/I:N/A:P/E:POC/RL:OF/RC:C |
| NVDNVD · Deferred | 4.0 | Low2.1 | 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/CR:X/IR:X/AR:X/MAV:X/MAC:X/MAT:X/MPR:X/MUI:X/MVC:X/MVI:X/MVA:X/MSC:X/MSI:X/MSA:X/S:X/AU:X/R:X/V:X/RE:X/U:X |
- EPSS (exploitation in 30 days)
- 0.33% · top 74% of all CVEs (11 Nov 2026)
- CISA SSVC
- Exploitation: poc · Automatable: no · Technical impact: partial
The list uses the assigner's score when there is one, then CISA's, then NVD's: Medium 5.3.
Affected products
postcss-selector-parser
- affected 6.1.0
- affected 6.1.1
- affected 6.1.2
- affected 7.1.0
- affected 7.1.1
- affected 7.1.2
- unaffected 6.1.3
- unaffected 7.1.3
Affected packages
From reviewed advisories of the GitHub Advisory Database.
- npmpostcss-selector-parserGHSA-w9m9-85wc-3x92 (opens in a new tab)
References
References7
- VDB-365321 | postcss-selector-parser AST Serialization container.js toString recursion (opens in a new tab)vdb-entrytechnical-description
- VDB-365321 | CTI Indicators (IOB, IOC, TTP, IOA) (opens in a new tab)signaturepermissions-required
- CVE-2026-9358 | CVE Analysis and Report (opens in a new tab)third-party-advisory
- Submit #813080 | postcss-selector-parser postcss <= 7.1.1 CWE-674: Uncontrolled Recursion (opens in a new tab)third-party-advisory
- https://gist.github.com/bx33661/581e3a38134601c04e19b4dfc9b459b9 (opens in a new tab)exploit
- https://github.com/postcss/postcss-selector-parser/commit/5bc698cef66f8abd12610dc623e5d67cbc0f869d (opens in a new tab)patch
- https://github.com/postcss/postcss-selector-parser/releases/tag/7.1.3 (opens in a new tab)patch
Sources
The same CVE in the primary databases and aggregators, to check against.
- CVE.org record (opens in a new tab)
- CVE List JSON (GitHub) (opens in a new tab)
- NVD (opens in a new tab)
- FIRST EPSS (opens in a new tab)
- EUVD EUVD-2026-31571 (opens in a new tab)
- OSV.dev (opens in a new tab)
- GitHub Advisory GHSA-w9m9-85wc-3x92 (opens in a new tab)
- CIRCL Vulnerability-Lookup (opens in a new tab)
Badge for a README or a ticket
[](https://cveledger.app/cve/CVE-2026-9358)Record last updated .