vLLM vulnerable to denial of service via OpenAI-compatible serving path

# vLLM vulnerable to denial of service via OpenAI-compatible serving path

https://gcdradar.vercel.app/incidents/vllm-vulnerable-to-denial-of-service-via-openai-compatible-s · AIR-2026-0718 · closed 2026-05-26

- Lane: Patch now
- Severity: 2 (Disclosed vulnerability)
- Fix status: Fix status unknown
- First reported: 2026-05-26
- AI role: Attack on AI
- Products: vllm
- CVE ids: CVE-2026-9540
- CVSS: 5.5

## Summary

An improper resource shutdown vulnerability exists in vLLM affecting the OpenAI-compatible serving path. The issue enables remote attackers to trigger a denial of service.

## What to do

No action recorded; read the sources below and the vendor's advisory.

## Latest updates

- 2026-05-26: CVE-2026-9540: A vulnerability was identified in vllm-project vllm 0.19.0. (https://nvd.nist.gov/vuln/detail/CVE-2026-9540)
- 2026-05-26: CVE-2026-9540: vllm has Improper Resource Shutdown or Release  (https://github.com/advisories/GHSA-98f3-hwg4-4rf7)

## Sources

- 2026-05-26 GitHub Advisory Database: CVE-2026-9540: vllm has Improper Resource Shutdown or Release  https://github.com/advisories/GHSA-98f3-hwg4-4rf7
- 2026-05-26 NVD: CVE-2026-9540: A vulnerability was identified in vllm-project vllm 0.19.0. https://nvd.nist.gov/vuln/detail/CVE-2026-9540

Verify against the vendor's advisory before changing production. Data CC BY-SA 4.0, https://gcdradar.vercel.app.