# CVE-2025-4742: XU-YIJIE grpo-flat grpo_vanilla.py main deserialization

> Local attackers can execute arbitrary code via unsafe deserialization in the main function of grpo_vanilla.py.

- **Severity:** Medium 4.8 (`CVSS:4.0/AV:L/AC:L/AT:N/PR:L/UI:N/VC:L/VI:L/VA:L/SC:N/SI:N/SA:N`)
- **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:** No
- **Published:** 16 May 2025
- **Updated:** 16 May 2025
- **Also known as:** GHSA-p9qv-6qqh-cc4q

## What is CVE-2025-4742?

CVE-2025-4742 is a medium-severity unsafe deserialization vulnerability in XU-YIJIE grpo-flat, published on 16 May 2025. It can only be exploited from the same machine or local network, with no action from the victim.

### Official description

A vulnerability classified as problematic has been found in XU-YIJIE grpo-flat up to 9024b43f091e2eb9bac65802b120c0b35f9ba856. Affected is the function main of the file grpo_vanilla.py. The manipulation leads to deserialization. Local access is required to approach this attack. Continious delivery with rolling releases is used by this product. Therefore, no version details of affected nor updated releases are available.

Weakness: CWE-502 (Deserialization of Untrusted Data), CWE-20 (Improper Input Validation)

## Which versions are affected by CVE-2025-4742?


## How do I fix CVE-2025-4742?

No fix has been published for CVE-2025-4742 yet. Limit exposure of the affected software until one is available.

## Is CVE-2025-4742 being exploited?

There is no known exploitation of CVE-2025-4742 in the wild and no public exploit code.

## Fix prompt for AI coding agents

```text
Check this codebase for CVE-2025-4742 and fix it if it is affected.

What it is: CVE-2025-4742 is a medium-severity unsafe deserialization vulnerability in XU-YIJIE grpo-flat, published on 16 May 2025. It can only be exploited from the same machine or local network, with no action from the victim.
Exploitation: There is no known exploitation of CVE-2025-4742 in the wild and no public exploit code.

Affected product: XU-YIJIE grpo-flat. 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-2025-4742/ (Markdown: https://insights.sbomify.com/CVE-2025-4742/index.md)
```

## Sources

- CVE record: https://www.cve.org/CVERecord?id=CVE-2025-4742
- NVD: https://nvd.nist.gov/vuln/detail/CVE-2025-4742
- OSV: https://osv.dev/vulnerability/CVE-2025-4742

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From sbomify Insights: https://insights.sbomify.com/CVE-2025-4742/
Summaries are generated and may contain mistakes; the official description above is the record.