Vulnerability Description
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.
CVSS Score
HIGH
Affected Products
| Vendor | Product | Versions |
|---|---|---|
| Vllm | Vllm | <= 0.29.0 |
Related Weaknesses (CWE)
References
- https://github.com/vllm-project/vllmProduct
- https://github.com/vllm-project/vllm/blob/v0.29.0/vllm/distributed/kv_transfer/kProduct
- https://github.com/vllm-project/vllm/pull/51505Issue TrackingPatch
- https://www.vulncheck.com/advisories/vllm-through-0.29.0-denial-of-service-via-nThird Party Advisory
FAQ
What is CVE-2026-94623?
CVE-2026-94623 is a vulnerability with a CVSS score of 7.5 (HIGH). 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 request...
How severe is CVE-2026-94623?
CVE-2026-94623 has been rated HIGH with a CVSS base score of 7.5/10. Review the CVSS metrics above for detailed severity breakdown.
Is there a patch for CVE-2026-94623?
Check the references section above for vendor advisories and patch information. Affected products include: Vllm Vllm.