CVE-2026-94623

vLLM through 0.29.0 Denial of Service via NIXL Multi-Prompt Assertion Failure

8.7 HighFix available

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.

Attack profile

How easy it is to exploit

Attack vector: Network
Complexity: Low
Privileges needed: None
User interaction: None

What an attacker can affect

Confidentiality: None
Integrity: None
Availability: High

Exploit likelihood

0.63%Up 0.2 points since Sep 22, 2026

What each source reports

CVE List Score used 8.7

vLLM through 0.29.0 Denial of Service via NIXL Multi-Prompt Assertion Failure

Record: CVE-2026-94623
CVSS 4.0: 8.7 HighCVSS:4.0/AV:N/AC:L/AT:N/PR:N/UI:N/VC:N/VI:N/VA:H/SC:N/SI:N/SA:N
CVSS 3.1: 7.5 HighCVSS:3.1/AV:N/AC:L/PR:N/UI:N/S:U/C:N/I:N/A:H
Weakness: CWE-617
Updated: 2026-11-02

EUVDEUVD-2026-84217 8.7

Record: EUVD-2026-84217
CVSS 4.0: 8.7 HighCVSS:4.0/AV:N/AC:L/AT:N/PR:N/UI:N/VC:N/VI:N/VA:H/SC:N/SI:N/SA:N
Updated: 2026-11-02

GitHub AdvisoriesGHSA-g3cp-v4cp-9xfq 8.7

vLLM through 0.29.0 contains a denial of service vulnerability in the NIXL connector's prefix...

Record: GHSA-g3cp-v4cp-9xfq
CVSS 4.0: 8.7 HighCVSS:4.0/AV:N/AC:L/AT:N/PR:N/UI:N/VC:N/VI:N/VA:H/SC:N/SI:N/SA:N/E:X/CR:X/IR:X/AR:X/MAV:X/MAC:X/MAT:X/MPR:X/MUI:X/MVC:X/MVI:X/MVA:X/MSC:X/MSI:X/MSA:X/S:X/AU:X/R:X/V:X/RE:X/U:X
CVSS 3.1: 7.5 HighCVSS:3.1/AV:N/AC:L/PR:N/UI:N/S:U/C:N/I:N/A:H
Weakness: CWE-617
Updated: 2026-11-02

NVD 8.7

Record: CVE-2026-94623
CVSS 4.0: 8.7 HighCVSS:4.0/AV:N/AC:L/AT:N/PR:N/UI:N/VC:N/VI:N/VA:H/SC:N/SI:N/SA:N/E:X/CR:X/IR:X/AR:X/MAV:X/MAC:X/MAT:X/MPR:X/MUI:X/MVC:X/MVI:X/MVA:X/MSC:X/MSI:X/MSA:X/S:X/AU:X/R:X/V:X/RE:X/U:X
CVSS 3.1: 7.5 HighCVSS:3.1/AV:N/AC:L/PR:N/UI:N/S:U/C:N/I:N/A:H
Weakness: CWE-617
Updated: 2026-11-02

OSV 8.7

vLLM through 0.29.0 Denial of Service via NIXL Multi-Prompt Assertion Failure

Record: CVE-2026-94623
CVSS 4.0: 8.7 HighCVSS:4.0/AV:N/AC:L/AT:N/PR:N/UI:N/VC:N/VI:N/VA:H/SC:N/SI:N/SA:N
Weakness: CWE-617
Updated: 2026-11-02

OSVPYSEC-2026-4005 8.7

Record: PYSEC-2026-4005
CVSS 4.0: 8.7 HighCVSS:4.0/AV:N/AC:L/AT:N/PR:N/UI:N/VC:N/VI:N/VA:H/SC:N/SI:N/SA:N/E:X/CR:X/IR:X/AR:X/MAV:X/MAC:X/MAT:X/MPR:X/MUI:X/MVC:X/MVI:X/MVA:X/MSC:X/MSI:X/MSA:X/S:X/AU:X/R:X/V:X/RE:X/U:X
Updated: 2026-11-02

Affected products

Affected packages

Affected packages
Package	Affected	Fixed
`vllm` PyPI	before 0.30.0, plus listed versions 0.0.10.1.00.1.10.1.20.1.3 Show 45 moreShow less 0.1.40.1.50.1.60.1.70.10.00.10.10.10.1.10.10.20.11.00.11.10.11.20.12.00.13.00.14.00.14.10.15.00.15.10.16.00.17.00.17.10.18.00.18.10.19.00.19.10.2.00.2.10.2.1.post10.2.20.2.30.2.40.2.50.2.60.2.70.20.00.20.10.20.20.21.00.22.00.22.10.23.00.24.00.25.00.25.10.26.00.27.0	0.30.0

History

History
Recorded	Changed	Sources
Nov 2, 2026	first indexed	CVE List, EUVD, GitHub Advisories, NVD, OSV

Dates are when Every CVE recorded each change. Upstream dates may differ.

In short

CVE-2026-94623 is a high vulnerability (CVSS 8.7) in Vllm, published September 21, 2026. No source lists public exploit code. EPSS puts the chance of exploitation in the next 30 days at 0.63%, the 50th percentile. Fixed in vllm 0.30.0.

References

This page doesn't list everything

Left out here: 47 versions. The JSON record has them.