Database/AI/ML frameworks & serving
vLLM: incomplete NIXL kv_transfer_params kills the decode engine with an uncaught KeyError
Impact
In prefill/decode disaggregated deployments using the NIXL connector, a request carrying an incomplete kv_transfer_params dictionary reaches EngineCore scheduling and raises an uncaught KeyError, terminating the decode engine. Every request routed to that engine then fails until an operator restarts it manually - there is no self-heal. One malformed request from any caller takes down a decode tier that many tenants share, and the GPUs it owns stop serving while weights reload.
Who can reach it
Any client that can reach the vLLM OpenAI-compatible API and set kv_transfer_params. No authentication required per the record. Only disaggregated deployments with the NIXL connector are affected.
What to do
Pick up the fix in vllm-project/vllm PR #54807 (no released version is named in the record; reported through 0.29.0). Rolling out is a container image update and a restart of the decode engines - drain traffic from each replica first, since the restart reloads model weights. If you cannot patch yet, have the fronting gateway reject or overwrite client-supplied kv_transfer_params.
References
Related entries
- vLLM: multi-prompt completion request trips a NIXL prefix-caching assertion and kills the decode workerCVE-2026-94623 · vLLM NIXL connector prefix caching (NixlBaseConnectorWorker._apply_prefix_caching)High
- vLLM: attacker-chosen P2P offload peers exhaust ZeroMQ contexts and crash EngineCoreCVE-2026-94624 · vLLM P2P KV offloading (OffloadingConnector TieringOffloadingSpec, ZeroMQ control)High
- vLLM: unvalidated tp_size in kv_transfer_params drives the decode worker into OOM-killCVE-2026-94626 · vLLM NIXL KV connector (unvalidated tp_size in kv_transfer_params)High
- vLLM: Mooncake transfer-ID collision leaks GPU KV cache blocks until restartCVE-2026-94627 · vLLM Mooncake KV connector (transfer-ID ownership of GPU KV cache blocks)High
- Gradio (`/queue/join`): SSRFCVE-2024-4325 · Gradio (`/queue/join`)High
- ONNX: Security-control bypass through 1.20.1CVE-2026-28500 · ONNXHigh
This entry is curated: imported from vendor advisories with machine assistance, not yet individually verified. Confirm against your vendor's advisory before acting, and report anything wrong.