Vulnerability in Vllm-Project Vllm
CVE-2026-94623
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 v3 metric
CVSS v3 base score 7.5 (High). Vector: CVSS:3.1/AV:N/AC:L/PR:N/UI:N/S:U/C:N/I:N/A:H.
Affected products
Weakness classification (CWE)
References
- disclosure@vulncheck.com (product)
- disclosure@vulncheck.com (technical-description)
- disclosure@vulncheck.com (issue-tracking, patch)
- disclosure@vulncheck.com (third-party-advisory)
Frequently asked questions
- What is CVE-2026-94623?
- CVE-2026-94623 is a high-severity vulnerability in Vllm-Project Vllm, classified under Reachable Assertion. CVSS score: 7.5/10. Published 2026-09-21.
- How severe is CVE-2026-94623?
- High severity. CVSS v3 base score is 7.5 out of 10.