Bug 2546182 (CVE-2026-105756)

Summary: CVE-2026-105756 vllm: vllm: Denial of Service via unvalidated cache salt in API requests
Product: [Other] Security Response Reporter: OSIDB Bzimport <bzimport>
Component: vulnerabilityAssignee: Product Security DevOps Team <prodsec-dev>
Status: NEW --- QA Contact:
Severity: medium Docs Contact:
Priority: medium    
Version: unspecifiedCC: alinfoot, bbrownin, dtrifiro, weaton
Target Milestone: ---Keywords: Security
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Hardware: All   
OS: Linux   
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A flaw was found in vllm. An authenticated remote attacker can cause a Denial of Service (DoS) by submitting an API request containing an invalid cache salt parameter with forbidden characters or excessive length. Because the application fails to validate the parameter before passing it to the internal caching component, the malformed input triggers an unhandled error during cache lookup. This failure causes the core engine process to terminate, disrupting service for all active users.
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Description OSIDB Bzimport 2026-10-05 23:01:20 UTC 
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.