Regular Expression Denial of Service in vLLM by VLLM Project
CVE-2025-48887
6.5MEDIUM
What is CVE-2025-48887?
vLLM, an inference and serving engine for large language models, is vulnerable to a Regular Expression Denial of Service (ReDoS). This vulnerability is caused by a complex and nested regular expression used for detecting tool calls, specifically found within the vllm/entrypoints/openai/tool_parsers/pythonic_tool_parser.py
file. Attackers can exploit this vulnerability to significantly degrade performance or render the service unavailable due to catastrophic backtracking caused by the regex pattern's multiple nested quantifiers and optional groups. A patch is available in version 0.9.0 to mitigate this issue.
Affected Version(s)
vllm >= 0.6.4, < 0.9.0