#VU121137 Inefficient regular expression complexity in vLLM - CVE-2025-48887
Published: January 9, 2026
Vulnerability identifier: #VU121137
Vulnerability risk: Medium
CVSSv4.0: CVSS:4.0/AV:N/AC:L/AT:N/PR:L/UI:N/VC:N/VI:N/VA:H/SC:N/SI:N/SA:N/E:U/U:Green
CVE-ID: CVE-2025-48887
CWE-ID: CWE-1333
Exploitation vector: Remote access
Exploit availability:
No public exploit available
Vulnerable software:
vLLM
vLLM
Software vendor:
vLLM
vLLM
Description
The vulnerability allows a remote user to perform a denial of service (DoS) attack.
The vulnerability exists due to insufficient input validation when processing untrusted input with a regular expressions in vllm/entrypoints/openai/tool_parsers/pythonic_tool_parser.py. A remote user can pass specially crafted data to the application and perform regular expression denial of service (ReDos) attack.
Remediation
Install updates from vendor's website.