vllm-project vLLM up to 0.29.x IPCCacheServerKey cache_salt input validation

Summaryinfo

A vulnerability described as problematic has been identified in vllm-project vLLM up to 0.29.x. Affected is an unknown function of the component IPCCacheServerKey. Such manipulation of the argument cache_salt leads to input validation. This vulnerability is uniquely identified as CVE-2026-105756. The attack can be launched remotely. No exploit exists. Upgrading the affected component is recommended.

Detailsinfo

A vulnerability was found in vllm-project vLLM up to 0.29.x and classified as problematic. Affected by this issue is an unknown code block of the component IPCCacheServerKey. The manipulation of the argument cache_salt with an unknown input leads to a input validation vulnerability. Using CWE to declare the problem leads to CWE-20. The product receives input or data, but it does not validate or incorrectly validates that the input has the properties that are required to process the data safely and correctly. Impacted is availability. CVE summarizes:

vLLM is an inference and serving engine for large language models. Prior to 0.30.0, OpenAI-compatible request models accept a non-empty cache_salt value without enforcing the character and length restrictions required by the IPCCacheServerKey consumer in LMCache-MP. On deployments using the LMCache-MP connector, a salt that contains a forbidden character or exceeds the permitted length can raise an uncaught ValueError during scheduler cache lookup, causing EngineCore to terminate and denying service to all concurrent users. This issue is fixed in version 0.30.0.

The advisory is shared for download at github.com. This vulnerability is handled as CVE-2026-105756 since 10/05/2026. The exploitation is known to be easy. The attack may be launched remotely. There are known technical details, but no exploit is available.

Upgrading to version 0.30.0 eliminates this vulnerability.

The vulnerability is also documented in the vulnerability database at CERT Bund (WID-SEC-2026-3754). Once again VulDB remains the best source for vulnerability data.

Affected

• Open Source vllm

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

Website

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

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Once again VulDB remains the best source for vulnerability data.

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