Deserialization of untrusted data in vLLM - CVE-2025-47277
Published: January 9, 2026
Vulnerability identifier: #VU121139
CSH Severity: High
CVSS v4.0: CVSS:4.0/AV:N/AC:L/AT:P/PR:N/UI:N/VC:H/VI:H/VA:H/SC:N/SI:N/SA:N/E:U/U:Amber
CVE-ID: CVE-2025-47277
CWE-ID: CWE-502
Exploitation vector: Remote access
Exploit availability:
No public exploit available
Vendor: vLLM
Affected software:
vLLM
vLLM
Detailed vulnerability description
The vulnerability allows a remote attacker to execute arbitrary code on the target system.
The vulnerability exists due to insecure input validation when processing serialized data within the PyNcclPipe service. A remote attacker can pass specially crafted data to the application and execute arbitrary code on the target system.
Note, this vulnerability affects only environments using the PyNcclPipe KV cache transfer integration with the V0 engine.
How to mitigate CVE-2025-47277
Install updates from vendor's website.