# CVE-2024-4067: Regular Expression Denial of Service in micromatch

> An attacker can cause a denial of service in applications using micromatch by submitting malicious input that triggers excessive regex backtracking.

- **Severity:** Medium 5.3 (`CVSS:3.1/AV:N/AC:L/PR:N/UI:N/S:U/C:N/I:N/A:L`)
- **Exploited in the wild:** Not known
- **Login needed:** Not needed
- **Attackable:** Over the internet
- **Victim action needed:** Not needed
- **Fix available:** Yes
- **Published:** 13 May 2024
- **Updated:** 17 Sep 2024
- **Also known as:** AZL-43999, AZL-44454, CLEANSTART-2026-PI37875, CLSA-2026-1774830268, CLSA-2026-1776731781, DEBIAN-CVE-2024-4067, GHSA-952p-6rrq-rcjv, MINI-6r7j-c6j7-2gcc, MINI-8qp3-74pm-827j, ROOT-APP-NPM-CVE-2024-4067, UBUNTU-CVE-2024-4067, openSUSE-SU-2024:14007-1

## What is CVE-2024-4067?

CVE-2024-4067 is a medium-severity denial of service vulnerability in micromatch, published on 13 May 2024. An attacker can exploit it over the internet without logging in, with no action from the victim.

### Official description

The NPM package `micromatch` prior to 4.0.8 is vulnerable to Regular Expression Denial of Service (ReDoS). The vulnerability occurs in `micromatch.braces()` in `index.js` because the pattern `.*` will greedily match anything. By passing a malicious payload, the pattern matching will keep backtracking to the input while it doesn't find the closing bracket. As the input size increases, the consumption time will also increase until it causes the application to hang or slow down. There was a merged fix but further testing shows the issue persists. This issue should be mitigated by using a safe pattern that won't start backtracking the regular expression due to greedy matching. This issue was fixed in version 4.0.8.

Weakness: CWE-1333 (Inefficient Regular Expression Complexity)

## Which versions are affected by CVE-2024-4067?

2 open source packages ship an affected version, including micromatch. It affects 1 product.


| Package | Ecosystem | Affected | Fixed in |
| --- | --- | --- | --- |
| `micromatch` | npm | All versions | 4.0.8 |
| `micromatch` | npm | All versions | 4.0.8 |

Products: Jonschlinkert Micromatch.

## How do I fix CVE-2024-4067?

Upgrade micromatch to 4.0.8 or later.

## Is CVE-2024-4067 being exploited?

There is no known exploitation of CVE-2024-4067 in the wild and no public exploit code.

## Fix prompt for AI coding agents

```text
Check this codebase for CVE-2024-4067 and fix it if it is affected.

What it is: CVE-2024-4067 is a medium-severity denial of service vulnerability in micromatch, published on 13 May 2024. An attacker can exploit it over the internet without logging in, with no action from the victim.
Exploitation: There is no known exploitation of CVE-2024-4067 in the wild and no public exploit code.

Affected packages and fixed versions:
- micromatch (npm): affected all versions; fixed in 4.0.8
- micromatch (npm): affected all versions; fixed in 4.0.8

Task:
1. Search the dependency manifests and lockfiles (for example package.json, package-lock.json, requirements.txt, poetry.lock, uv.lock, pom.xml, build.gradle, go.mod, Cargo.lock, Gemfile.lock) and any Dockerfiles for the affected packages, including transitive dependencies.
2. If an affected version is in use, upgrade it to the fixed version for its release line with the project's package manager, so the lockfile is regenerated. Prefer the smallest upgrade that fixes it.
3. If there is no fix, or the upgrade would break the build, do not guess: explain the risk and the safest workaround instead.
4. Run the tests and summarise what changed and why.
5. If nothing in the project is affected, say so and change nothing.

Reference: https://insights.sbomify.com/CVE-2024-4067/ (Markdown: https://insights.sbomify.com/CVE-2024-4067/index.md)
```

## Sources

- CVE record: https://www.cve.org/CVERecord?id=CVE-2024-4067
- NVD: https://nvd.nist.gov/vuln/detail/CVE-2024-4067
- OSV: https://osv.dev/vulnerability/CVE-2024-4067

---
From sbomify Insights: https://insights.sbomify.com/CVE-2024-4067/
Summaries are generated and may contain mistakes; the official description above is the record.