CVE-2025-48942 vLLM DOS: Remotely kill vllm over http with invalid JSON schema

What is CVE-2025-48942?

CVE-2025-48942 is a medium-severity vulnerability in Vllm Vllm, published on 30 May 2025.

Official description

vLLM is an inference and serving engine for large language models (LLMs). In versions 0.8.0 up to but excluding 0.9.0, hitting the /v1/completions API with a invalid json_schema as a Guided Param kills the vllm server. This vulnerability is similar GHSA-9hcf-v7m4-6m2j/CVE-2025-48943, but for regex instead of a JSON schema. Version 0.9.0 fixes the issue.

Weakness: CWE-248

Which versions are affected by CVE-2025-48942?

3 open source packages ship an affected version, including vllm. It affects 1 product.

Products include Vllm Vllm.

How do I fix CVE-2025-48942?

Upgrade vllm to 0.9.0 or later.

Is CVE-2025-48942 being exploited?

It is not confirmed as exploited in the wild, but public exploit code for CVE-2025-48942 exists.

Other vulnerabilities in Vllm Vllm

• CVE-2025-32444 vLLM Vulnerable to Remote Code Execution via Mooncake Integration Critical 10.0
• CVE-2026-22778 vLLM leaks a heap address when PIL throws an error Critical 9.8
• CVE-2025-47277 vLLM Allows Remote Code Execution via PyNcclPipe Communication Service Critical 9.8
• CVE-2024-11041 Remote Code Execution in vllm-project/vllm Critical 9.8
• CVE-2026-48746 vLLM: OpenAI auth bypass Critical 9.1

All Vllm Vllm vulnerabilities

Sources

• CVE record
• NVD
• OSV
• GitHub advisory
• How this page is made

Also known as GHSA-6qc9-v4r8-22xg, PYSEC-2025-54.