CVE-2025-9141

An unsafe deserialization vulnerability allows any authenticated user to execute arbitrary code on the server if they are able to get the model to pass the code as an argument to a tool call.

Details

vLLM's Qwen3 Coder tool parser contains a code execution path that uses Python's eval() function to parse tool call parameters. This occurs during the parameter conversion process when the parser attempts to handle unknown data types.

This code path is reached when:

1. Tool calling is enabled (--enable-auto-tool-choice)
2. The qwen3_coder parser is specified (--tool-call-parser qwen3_coder)
3. The parameter type is not explicitly defined or recognized

Remote Code Execution via Python's eval() function.

Untrusted serialized data is processed by a deserializer that can instantiate arbitrary objects or execute code as a side effect. Typical impact: arbitrary code execution or logic abuse.

CVE-2025-9141 has a CVSS score of 8.8 (High). The vector is network-reachable, low privileges required, and no user interaction. A CVSS score reflects the worst-case severity of the vulnerability, not your specific exposure. Whether this affects your application depends on whether the vulnerable code is present and reachable in your environment. A fixed version is available (0.10.1.1); upgrading removes the vulnerable code path.

Kodem intelligence

1. What is CVE-2025-9141? CVE-2025-9141 is a high-severity insecure deserialization vulnerability in vllm (pip), affecting versions >= 0.10.0, < 0.10.1.1. It is fixed in 0.10.1.1. Untrusted serialized data is processed by a deserializer that can instantiate arbitrary objects or execute code as a side effect.
2. How severe is CVE-2025-9141? CVE-2025-9141 has a CVSS score of 8.8 (High). This score reflects the worst-case severity of the vulnerability, not your specific exposure. Whether it represents real risk in your environment depends on whether the vulnerable code is present and reachable.
3. Which versions of vllm are affected by CVE-2025-9141? vllm (pip) versions >= 0.10.0, < 0.10.1.1 is affected.
4. Is there a fix for CVE-2025-9141? Yes. CVE-2025-9141 is fixed in 0.10.1.1. Upgrade to this version or later.
5. Is CVE-2025-9141 exploitable, and should I be worried? Whether CVE-2025-9141 is exploitable in your environment depends on whether the vulnerable code is present and reachable. A CVSS score is a worst-case rating; it does not account for your specific deployment, configuration, or usage patterns. Kodem, an Intelligent Application Security platform, uses runtime intelligence to show which vulnerabilities actually execute in production, so you can focus on the ones that represent real risk. Get a demo
6. What actually determines whether CVE-2025-9141 is exploitable, and how bad it is? Exploitability and impact are not fixed properties of a CVE. They depend on runtime truth: whether the vulnerable code is present, reachable, and actually executes in your application. A high CVSS score on a dependency that never runs is not the same as real risk. Kodem, an Intelligent Application Security platform, uses runtime intelligence to reveal which vulnerabilities actually execute in production, so teams prioritize the ones that genuinely matter.
7. How do I fix CVE-2025-9141? Upgrade vllm to 0.10.1.1 or later.