# CVE-2025-50537: Denial of service in n/a

> An attacker can cause a stack overflow and denial of service in ESLint by providing objects with circular references during rule testing.

- **Severity:** Medium 5.5 (`CVSS:3.1/AV:L/AC:L/PR:N/UI:R/S:U/C:N/I:N/A:H`)
- **Exploited in the wild:** Not known
- **Login needed:** Not needed
- **Attackable:** Local or same network only
- **Victim action needed:** A user has to click or open something
- **Fix available:** Yes
- **Published:** 26 Jan 2026
- **Updated:** 26 Jan 2026
- **Also known as:** MINI-4j9p-5c8c-3338, MINI-9r6r-cv27-vf5r, MINI-r248-vcpg-rwjr, MINI-w6vx-g9wp-c2hg, MINI-w9rh-h6x7-h6qr, ROOT-APP-NPM-CVE-2025-50537, UBUNTU-CVE-2025-50537

## What is CVE-2025-50537?

CVE-2025-50537 is a medium-severity denial of service vulnerability in n/a, published on 26 Jan 2026. It can only be exploited from the same machine or local network, and only if a user opens a file or follows a link.

### Official description

Stack overflow vulnerability in eslint before 9.26.0 when serializing objects with circular references in eslint/lib/shared/serialization.js. The exploit is triggered via the RuleTester.run() method, which validates test cases and checks for duplicates. During validation, the internal function checkDuplicateTestCase() is called, which in turn uses the isSerializable() function for serialization checks. When a circular reference object is passed in, isSerializable() enters infinite recursion, ultimately causing a stack overflow.

Weakness: CWE-674 (Uncontrolled Recursion)

## Which versions are affected by CVE-2025-50537?

It affects 1 product.


Products: Openjsf Eslint.

## How do I fix CVE-2025-50537?

Upgrade to a fixed version.

## Is CVE-2025-50537 being exploited?

It is not confirmed as exploited in the wild, but public exploit code for CVE-2025-50537 exists.

## Fix prompt for AI coding agents

```text
Check this codebase for CVE-2025-50537 and fix it if it is affected.

What it is: CVE-2025-50537 is a medium-severity denial of service vulnerability in n/a, published on 26 Jan 2026. It can only be exploited from the same machine or local network, and only if a user opens a file or follows a link.
Exploitation: It is not confirmed as exploited in the wild, but public exploit code for CVE-2025-50537 exists.

Affected product: n/a. No package-level version data is available, so check the vendor advisory linked from the reference page.

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-2025-50537/ (Markdown: https://insights.sbomify.com/CVE-2025-50537/index.md)
```

## Sources

- CVE record: https://www.cve.org/CVERecord?id=CVE-2025-50537
- NVD: https://nvd.nist.gov/vuln/detail/CVE-2025-50537
- OSV: https://osv.dev/vulnerability/CVE-2025-50537

---
From sbomify Insights: https://insights.sbomify.com/CVE-2025-50537/
Summaries are generated and may contain mistakes; the official description above is the record.