# CVE-2026-31252: FunAudioLLM CosyVoice insecure deserialization in model loading

Source: https://junglewise.ai/threats/cve-2026-31252-funaudiollm-cosyvoice-insecure-deserialization-in-model-loading  
Publisher: Junglewise Threat Intelligence, https://junglewise.ai/threats  
Published: 2026-05-11. Updated: 2026-05-14  
License: CC BY 4.0 with a link back

CVE-2026-31252 · Severity: medium · CVSS 5.7 · Published 2026-05-11

CosyVoice, a multi-lingual voice generation framework, is vulnerable to a security flaw in how it loads AI model files. If a user is tricked into loading a malicious model file from an untrusted source, an attacker can execute unauthorized commands on the user's computer. This could lead to a full system compromise, data theft, or the installation of malware.

Technologies: [FunAudioLLM CosyVoice](https://junglewise.ai/threats/technologies/cosyvoice). Vendors: [FunAudioLLM](https://junglewise.ai/threats/vendors/funaudiollm).

## Quick answers

**Is CVE-2026-31252 exploited in the wild?** No. Junglewise Threat Intelligence has no report of CVE-2026-31252 being exploited in the wild.

**How severe is CVE-2026-31252?** Medium severity, with a CVSS score of 5.7, published 11 May 2026.

**Which products and versions are affected?** FunAudioLLM CosyVoice up to commit 6e01309e01bc93bbeb83bdd996b1182a81aaf11e.

**Is there a fix for CVE-2026-31252?** No fixed version is recorded yet. Check the vendor's advisory in the references below. If you run it, Junglewise drafts a mitigation that fits your setup and applies it once you approve, with senior security engineers behind it.

**How is CVE-2026-31252 attacked?** It is attacked with local access, in a software library.

**Am I affected by CVE-2026-31252?** Check whether you run FunAudioLLM CosyVoice at an affected version. Junglewise does that check for you around the clock: connect your code, cloud and domains, and it matches new vulnerabilities like this one against what you actually run and tells you when one reaches you.

## Technical details

CosyVoice (up to commit 6e01309e01bc93bbeb83bdd996b1182a81aaf11e) is vulnerable to insecure deserialization (CWE-502) within its model loading component. The application utilizes the `torch.load()` function to process model weight files (such as llm.pt, flow.pt, and hift.pt) without setting the `weights_only=True` parameter. Because `torch.load` uses the Python pickle module by default, it can be coerced into deserializing arbitrary Python objects. An attacker can exploit this by providing a malicious model directory; when a victim points the CosyVoice Web UI to this directory, the framework executes arbitrary code embedded in the model files.

## Affected products

- FunAudioLLM CosyVoice up to commit 6e01309e01bc93bbeb83bdd996b1182a81aaf11e

## Timeline

- 2026-05-11: advisory: CVE-2026-31252 published by NVD

## References

- [https://github.com/FunAudioLLM/CosyVoice](https://github.com/FunAudioLLM/CosyVoice)
- [https://www.notion.so/CVE-2026-31252-35d1e139318881ef8acfcd877a432569](https://www.notion.so/CVE-2026-31252-35d1e139318881ef8acfcd877a432569)

## Related threats

- [FunAudioLLM CosyVoice insecure deserialization in model loading](https://junglewise.ai/threats/cve-2026-31232-funaudiollm-cosyvoice-insecure-deserialization-in-model-loading)
- [FunAudioLLM CosyVoice insecure deserialization in gRPC server](https://junglewise.ai/threats/cve-2026-31251-funaudiollm-cosyvoice-insecure-deserialization-in-grpc-server)
- [FunAudioLLM CosyVoice insecure deserialization in average_model.py](https://junglewise.ai/threats/cve-2026-31250-funaudiollm-cosyvoice-insecure-deserialization-in-average-model)
- [FunAudioLLM CosyVoice insecure deserialization in make_parquet_list.py](https://junglewise.ai/threats/cve-2026-31249-funaudiollm-cosyvoice-insecure-deserialization-in-make-parquet)