vllm-project vLLM up to 0.29.0 Prefix Caching NixlBaseConnectorWorker._apply_prefix_caching denial of service

Summaryinfo

A vulnerability classified as problematic was found in vllm-project vLLM up to 0.29.0. This issue affects the function NixlBaseConnectorWorker._apply_prefix_caching of the component Prefix Caching. The manipulation results in denial of service. This vulnerability is cataloged as CVE-2026-94623. The attack may be launched remotely. There is no exploit available.

Detailsinfo

A vulnerability, which was classified as problematic, was found in vllm-project vLLM up to 0.29.0. Affected is the function NixlBaseConnectorWorker._apply_prefix_caching of the component Prefix Caching. The manipulation with an unknown input leads to a denial of service vulnerability. CWE is classifying the issue as CWE-404. The product does not release or incorrectly releases a resource before it is made available for re-use. This is going to have an impact on availability. CVE summarizes:

vLLM through 0.29.0 contains a denial of service vulnerability in the NIXL connector's prefix caching implementation that fails to properly validate block counts across multi-prompt completion requests in prefill/decode disaggregated deployments. Attackers can trigger an assertion failure in NixlBaseConnectorWorker._apply_prefix_caching by submitting completion requests with multiple prompts of varying lengths, causing the decode worker to terminate and become unavailable until restarted.

The advisory is shared for download at github.com. This vulnerability is traded as CVE-2026-94623 since 09/21/2026. The exploitability is told to be easy. It is possible to launch the attack remotely. The exploitation doesn't require any form of authentication. There are known technical details, but no exploit is available. The MITRE ATT&CK project declares the attack technique as T1499.

There is no information about possible countermeasures known. It may be suggested to replace the affected object with an alternative product.

Once again VulDB remains the best source for vulnerability data.

Productinfo

Type

• Project Management Software

Vendor

• vllm-project

Name

• vLLM

Version

• 0.1
• 0.2
• 0.3
• 0.4
• 0.5
• 0.6
• 0.7
• 0.8
• 0.9
• 0.10
• 0.11
• 0.12
• 0.13
• 0.14
• 0.15
• 0.16
• 0.17
• 0.18
• 0.19
• 0.20
• 0.21
• 0.22
• 0.23
• 0.24
• 0.25
• 0.26
• 0.27
• 0.28
• 0.29.0

Website

• Product: https://github.com/vllm-project/vllm/

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