CVE-2026-31251 Deserialization in n/a
An attacker can execute arbitrary code by providing malicious model files to a CosyVoice gRPC server that uses insecure deserialization.
- Exploited in the wild
- Not known
- Login needed
- Not needed
- Attackable
- Over the internet
- Victim action needed
- Not needed
- Fix
- None listed
What is CVE-2026-31251?
CVE-2026-31251 is a high-severity unsafe deserialization vulnerability in n/a, published on 11 May 2026. An attacker can exploit it over the internet without logging in, with no action from the victim.
Official description
CosyVoice thru commit 6e01309e01bc93bbeb83bdd996b1182a81aaf11e (2025-30-21) contains an insecure deserialization vulnerability (CWE-502) in its gRPC server component. When the server starts, it loads the speech synthesis model from a user-specified directory using torch.load() without enabling the weights_only=True security parameter. This allows the deserialization of arbitrary Python objects via the pickle module. An attacker can exploit this by providing malicious model files within a directory. When a victim starts the gRPC server pointing to this directory, arbitrary code is executed on the victim's system during server initialization.
Which versions are affected by CVE-2026-31251?
How do I fix CVE-2026-31251?
No fix has been published for CVE-2026-31251 yet. Limit exposure of the affected software until one is available.
Upgrade, and only deserialise data from trusted sources or with an allow-list of types. More about Unsafe deserialization.
Is CVE-2026-31251 being exploited?
There is no known exploitation of CVE-2026-31251 in the wild and no public exploit code.
Sources
Also known as GHSA-7mm4-fwjj-qfpc.