CVE-2026-94622: vLLM through 0.29.0 Denial of Service via Incomplete NIXL KV Transfer Metadata
vLLM versions through 0.29.0 contain a denial of service vulnerability in the NIXL connector's metadata handling for prefill/decode disaggregated deployments. Attackers can send requests with incomplete kvtransferparams dictionary entries to trigger an uncaught KeyError in EngineCore scheduling, causing the decode engine to terminate and making all routed requests fail until manual restart.
Affected Software
Event History
Frequently Asked Questions
Which deployments are exposed to this denial of service?
The issue affects vLLM deployments using the NIXL connector for prefill/decode disaggregation. The failure occurs in EngineCore scheduling on the decode engine, so routed requests to that engine fail after it terminates.
What must an attacker do to trigger the failure?
An attacker can send a request containing incomplete entries in the kv_transfer_params dictionary. No privileges or user interaction are required according to the supplied CVSS vector.
Are requests automatically restored after exploitation?
No. The decode engine terminates, and routed requests continue to fail until the engine is manually restarted.