MediumVulnerabilityLLM-specific

CVE-2026-9540: vllm-project vllm denial of service in OpenAI-compatible serving path

Source: NVD(opens in a new tab)
Identifier: CVE-2026-9540
Published: May 26, 2026
Record updated: October 9, 2026

Affected: vllm <= 0.19.0
Fixed in: No fixed version was stated when the source was last read.
Known exploitation: Not listed in the CISA Known Exploited Vulnerabilities catalog at the last check.
EPSS: 0.7%

Summary

CVE-2026-9540 affects vllm-project vllm 0.19.0 and lies in unspecified processing of the OpenAI-compatible Serving Path. Remote manipulation of this component leads to denial of service, and the exploit is publicly available. The CVSS 4.0 base score from CNA VulDB is 5.5 (MEDIUM), and the weakness is CWE-404, Improper Resource Shutdown or Release.

Mitigation

The pull request to fix this issue awaits acceptance. No fixed version is stated.

Details

Scores and exploitation

CVSS score: 5.3(medium)
CVSS vector: CVSS:3.1/AV:N/AC:L/PR:N/UI:N/S:U/C:N/I:N/A:L
Attack vector: network
Attack complexity: low
Privileges required: none
User interaction: none
EPSS: 0.7%Estimated probability that this CVE is exploited in the next 30 days, from the FIRST Exploit Prediction Scoring System. Read on October 13, 2026.
Disclosure date: May 26, 2026

Weaknesses and techniques

Weakness (CWE): CWE-404

Affected

Packages: vllm@<= 0.19.0

Classification

Attack type: Denial of service
Attack sophistication: Trivial
AI component targeted: Inference
Impact: Availability
Labels: security

How this record was produced

Summaries, mitigations and labels on this page are generated automatically from the source. The linked source is authoritative. The source gives this advisory a description and no title, so the title above is a headline generated from the source text.

Original source: https://nvd.nist.gov/vuln/detail/CVE-2026-9540

First tracked: May 26, 2026 at 11:31 AM ET, from NVD/CVE Database

Classifier: claude-haiku-5-5, prompt v4

Classifier confidence: 90% (self-assessed)

Affected packages in the Exposure Registry

Matched by package name and ecosystem. Each entry shows whether the package delegates to a language model and how many tracked packages depend on it.

vllmPyPILLM dependency since 2023-08-25 · 15 tracked dependents

Topics

Inference infrastructure

Summary

Mitigation

Affected packages in the Exposure Registry

Topics

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