vLLM allows clients to crash the openai server with invalid regex
Impact
A denial of service bug caused the vLLM server to crash if an invalid regex was provided while using structured output. This vulnerability is similar to GHSA-6qc9-v4r8-22xg, but for regex instead of a JSON schema.
Issue with more details: https://github.com/vllm-project/vllm/issues/17313
Patches
Affected software
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| Platform | Package | Vulnerable versions | Fixed in |
|---|---|---|---|
| Python (PyPI) | vllm | >= 0.8.0, < 0.9.0 | 0.9.0 |
References
- https://github.com/vllm-project/vllm/security/advisories/GHSA-9hcf-v7m4-6m2j
- https://github.com/vllm-project/vllm/commit/08bf7840780980c7568c573c70a6a8db94fd45ff
- https://github.com/vllm-project/vllm/pull/17623
- https://github.com/vllm-project/vllm/issues/17313
- https://nvd.nist.gov/vuln/detail/CVE-2025-48943
- https://github.com/pypa/advisory-database/tree/main/vulns/vllm/PYSEC-2025-55.yaml
- https://github.com/vllm-project/vllm
- CVSS vector
CVSS:3.1/AV:N/AC:L/PR:L/UI:N/S:U/C:N/I:N/A:H- Weakness (CWE)
CWE-248- Platform
- Python (PyPI)
- Package
vllm- Disclosed
- 28.05.2025
- Updated
- 11.10.2026 14:19
Sources and licenses
OSV / GitHub Advisory Database - PYSEC-2025-55 - PyPA Advisory Database; CC BY 4.0
OSV / GitHub Advisory Database - GHSA-9hcf-v7m4-6m2j - CC BY 4.0
Vulnerability history: vllm
All published vulnerabilities of this package (Python (PyPI)), newest first. Shows whether this is a one-off slip or a package that needs watching.
- Total entries
- 94
- First → latest
- 09.2024 10.2026
- Without a fix
- 5
- Exploited in attacks
- 0
Severity breakdown
- Critical 9
- High 23
- Medium 47
- Low 4
- Unrated 11
Disclosures per year
- 2024: 2
- 2025: 30
- 2026: 62
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vLLM allows clients to crash the openai server with invalid regex this entry
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