# CVE-2025-9308: yarnpkg Yarn request-manager.js setOptions redos

> A local attacker can cause a denial of service in Yarn via inefficient regular expression complexity in the request manager.

- **Severity:** Medium 4.8 (`CVSS:4.0/AV:L/AC:L/AT:N/PR:L/UI:N/VC:N/VI:N/VA:L/SC:N/SI:N/SA:N/E:X`)
- **Exploited in the wild:** Not known
- **Login needed:** Any signed-in user
- **Attackable:** Local or same network only
- **Victim action needed:** Not needed
- **Fix available:** Yes
- **Published:** 21 Aug 2025
- **Updated:** 21 Aug 2025
- **Also known as:** DEBIAN-CVE-2025-9308, GHSA-pfv3-xh9q-f4rq, MINI-x9wf-vrp9-qqff, UBUNTU-CVE-2025-9308

## What is CVE-2025-9308?

CVE-2025-9308 is a medium-severity denial of service vulnerability in yarnpkg Yarn, published on 21 Aug 2025. It can only be exploited from the same machine or local network, with no action from the victim.

### Official description

A vulnerability has been found in yarnpkg Yarn up to 1.22.22. This impacts the function setOptions of the file src/util/request-manager.js. Such manipulation leads to inefficient regular expression complexity. Local access is required to approach this attack. This vulnerability only affects products that are no longer supported by the maintainer.

Weakness: CWE-400 (Uncontrolled Resource Consumption), CWE-1333 (Inefficient Regular Expression Complexity)

## Which versions are affected by CVE-2025-9308?

It affects 1 product.


Products: Yarnpkg Yarn.

## How do I fix CVE-2025-9308?

Product is end of life, replace it.

## Is CVE-2025-9308 being exploited?

It is not confirmed as exploited in the wild, but public exploit code for CVE-2025-9308 exists.

## Other vulnerabilities in yarnpkg Yarn

- [CVE-2019-5448](https://insights.sbomify.com/CVE-2019-5448/): Missing Encryption of Sensitive Data in yarn (high 8.1)
- [CVE-2019-10773](https://insights.sbomify.com/CVE-2019-10773/): Yarn Improper link resolution before file access (Link Following) (high 7.8)
- [CVE-2021-4435](https://insights.sbomify.com/CVE-2021-4435/): Yarn: untrusted search path (high 7.7)
- [CVE-2020-8131](https://insights.sbomify.com/CVE-2020-8131/): Path Traversal in Yarn (high 7.5)
- [CVE-2019-15608](https://insights.sbomify.com/CVE-2019-15608/): TOCTOU Race Condition in Yarn (medium 5.9)

## Fix prompt for AI coding agents

```text
Check this codebase for CVE-2025-9308 and fix it if it is affected.

What it is: CVE-2025-9308 is a medium-severity denial of service vulnerability in yarnpkg Yarn, published on 21 Aug 2025. It can only be exploited from the same machine or local network, with no action from the victim.
Exploitation: It is not confirmed as exploited in the wild, but public exploit code for CVE-2025-9308 exists.

Affected product: yarnpkg Yarn. 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-2025-9308/ (Markdown: https://insights.sbomify.com/CVE-2025-9308/index.md)
```

## Sources

- CVE record: https://www.cve.org/CVERecord?id=CVE-2025-9308
- NVD: https://nvd.nist.gov/vuln/detail/CVE-2025-9308
- OSV: https://osv.dev/vulnerability/CVE-2025-9308

---
From sbomify Insights: https://insights.sbomify.com/CVE-2025-9308/
Summaries are generated and may contain mistakes; the official description above is the record.