CVE-2026-94623CWE-617

CVE-2026-94623

High · published September 22, 2026

CVSS v3.1
7.5
EPSS
1%
Percentile
49.4
In the wild
Unconfirmed
What it is

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.

The record
Technical detail
CVSS v3.1
7.5 · HIGH
Vector
CVSS:3.1/AV:N/AC:L/PR:N/UI:N/S:U/C:N/I:N/A:H
CVSS v4.0
8.7 · CVSS:4.0/AV:N/AC:L/AT:N/PR:N/UI:N/VC:N/VI:N/VA:H/SC:N/SI:N/SA:N
EPSS
0.00627 · 49.4th percentile
Weakness
CWE-617 · Reachable Assertion
Published
2026-09-22T02:17Z
Affected products (1)
ProductVersionsFixed in
vllm/vllm≤ 0.29.0—
References (4)
https://github.com/vllm-project/vllm · [email protected]https://github.com/vllm-project/vllm/blob/v0.29.0/vllm/distributed/kv_transfer/kv_connector/v1/nixl/base_worker.py#L2642-L2646 · [email protected]https://github.com/vllm-project/vllm/pull/51505 · [email protected]https://www.vulncheck.com/advisories/vllm-through-0.29.0-denial-of-service-via-nixl-multi-prompt-assertion-failure · [email protected]
EPSS history
Timeline
  • 23 SEP 03:49Z
    EPSS moved — → 0%
    epss
  • 21 SEP 22:04Z
    vLLM through 0.29.0 Denial of Service via NIXL Multi-Prompt Assertion Failure
    cvelistv5