@eslint/plugin-kit is vulnerable to Regular Expression Denial of Service attacks through ConfigCommentParser
Summary
The ConfigCommentParser#parseJSONLikeConfig API is vulnerable to a Regular Expression Denial of Service (ReDoS) attack in its only argument.
Details
The regular expression at packages/plugin-kit/src/config-comment-parser.js:158 is vulnerable to a quadratic runtime attack because the grouped expression is not anchored. This can be solved by prepending the regular expression with [^-a-zA-Z0-9/].
PoC
const { ConfigCommentParser } = require("@eslint/plugin-kit");
const str = `${"A".repeat(1000000)}?: 1 B: 2`;
console.log("start")
var parser = new ConfigCommentParser();
console.log(parser.parseJSONLikeConfig(str));
console.log("end")
// run `npm i @eslint/plugin-kit@0.3.3` and `node attack.js`
// then the program will stuck forever with high CPU usageImpact
This is a Regular Expression Denial of Service attack which may lead to blocking execution and high CPU usage.
Affected software
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| Platform | Package | Vulnerable versions | Fixed in |
|---|---|---|---|
| npm package | @eslint/plugin-kit | < 0.3.4 | 0.3.4 |
References
- CVSS vector
CVSS:4.0/AV:N/AC:L/AT:P/PR:L/UI:N/VC:N/VI:N/VA:L/SC:N/SI:N/SA:N- Weakness (CWE)
CWE-1333- Platform
- npm
- Package
@eslint/plugin-kit- Disclosed
- 18.07.2025
- Updated
- 11.10.2026 10:22
Sources and licenses
OSV / GitHub Advisory Database - GHSA-xffm-g5w8-qvg7 - CC BY 4.0
Vulnerability history: @eslint/plugin-kit
All published vulnerabilities of this package (npm package), newest first. Shows whether this is a one-off slip or a package that needs watching.
- Total entries
- 2
- First → latest
- 11.2024 07.2025
- Without a fix
- 0
- Exploited in attacks
- 0
Severity breakdown
- Low 2
Disclosures per year
- 2024: 1
- 2025: 1
- 2026: 0
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@eslint/plugin-kit is vulnerable to Regular Expression Denial of Service attacks through ConfigCommentParser this entry
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