Answer in brief
CVE-2026-9358 records a Low severity (CVSS 4.3) vulnerability in postcss-selector-parser allows denial of service through uncontrolled AST recursion. The current sources do not mark it as known exploited. The current feed maps postcss-selector-parser (npm), postcss-selector-parser (npm). Check affected ranges and fixed versions before updating.
Analysis pending evidence review
HOL Guard separates source facts from reviewed analysis. See the methodology.
CVSS is 4.3. The current sources do not mark it as known exploited. Treat this as a source-backed prioritization signal, not a statement about your environment.
Analysis status
Analysis pending evidence review
Factual feed record only; HOL analysis is not approved for indexing. Read the methodology.
The current feed maps postcss-selector-parser (npm), postcss-selector-parser (npm). Check affected ranges and fixed versions before updating.
| Package | Affected range | Fixed version |
|---|---|---|
| postcss-selector-parsernpm | >=6.1.0,<6.1.3 | 6.1.3 |
| postcss-selector-parsernpm | >=7.1.0,<7.1.3 | 7.1.3 |
Published upstream
May 26, 2026
Evidence: source:ghsa:source_dates:source-dates:recordSource modified
Sep 1, 2026
Evidence: source:ghsa:source_dates:source-dates:recordFirst seen by HOL
Sep 1, 2026
A vulnerability was determined in postcss-selector-parser before 6.1.3 and 7.1.1. 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. 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)."
Quoted source text, attributed separately from HOL analysis.