# CVE-2026-31252: Deserialization in n/a

> Attackers can execute arbitrary code by providing malicious model files to CosyVoice, which insecurely deserializes them during loading.

- **Severity:** Medium 5.7 (`CVSS:3.1/AV:L/AC:L/PR:L/UI:R/S:C/C:L/I:L/A:L`)
- **Exploited in the wild:** Not known
- **Login needed:** Any signed-in user
- **Attackable:** Local or same network only
- **Victim action needed:** A user has to click or open something
- **Fix available:** No
- **Published:** 11 May 2026
- **Updated:** 12 May 2026
- **Also known as:** GHSA-4xxc-9mf8-p66h

## What is CVE-2026-31252?

CVE-2026-31252 is a medium-severity unsafe deserialization vulnerability in n/a, published on 11 May 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

CosyVoice thru commit 6e01309e01bc93bbeb83bdd996b1182a81aaf11e (2025-30-21) contains an insecure deserialization vulnerability (CWE-502) in its model loading component. The framework uses torch.load() to load model weight files (e.g., llm.pt, flow.pt, hift.pt) without enabling the security-restrictive weights_only=True parameter. This allows the deserialization of arbitrary Python objects via the pickle module. An attacker can exploit this by providing a malicious model directory containing specially crafted model files. When a victim starts the CosyVoice Web UI pointing to this directory, arbitrary code is executed on the victim's system during the model loading process.

Weakness: CWE-94 (Improper Control of Generation of Code), CWE-915 (Improperly Controlled Modification of Dynamically-Determined Object Attributes)

## Which versions are affected by CVE-2026-31252?


## How do I fix CVE-2026-31252?

No fix has been published for CVE-2026-31252 yet. Limit exposure of the affected software until one is available.

## Is CVE-2026-31252 being exploited?

There is no known exploitation of CVE-2026-31252 in the wild and no public exploit code.

## Fix prompt for AI coding agents

```text
Check this codebase for CVE-2026-31252 and fix it if it is affected.

What it is: CVE-2026-31252 is a medium-severity unsafe deserialization vulnerability in n/a, published on 11 May 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: There is no known exploitation of CVE-2026-31252 in the wild and no public exploit code.

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-2026-31252/ (Markdown: https://insights.sbomify.com/CVE-2026-31252/index.md)
```

## Sources

- CVE record: https://www.cve.org/CVERecord?id=CVE-2026-31252
- NVD: https://nvd.nist.gov/vuln/detail/CVE-2026-31252
- OSV: https://osv.dev/vulnerability/CVE-2026-31252

---
From sbomify Insights: https://insights.sbomify.com/CVE-2026-31252/
Summaries are generated and may contain mistakes; the official description above is the record.