CVE-2026-94623

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.

Overview

State: PUBLISHED
Assigner (CNA): VulnCheck
CVSS severity: HIGH
CVSS score: 8.7 / 10
CVSS vector: 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
Effective score: 8.7 / 10 HIGH source: CNA overview
CWE(s): CWE-617
Reserved: 2026-09-21
Published: 2026-09-21 22:04 UTC
Last updated: 2026-09-21 22:04 UTC
Source: https://raw.githubusercontent.com/CVEProject/cvelistV5/main/cves/2026/94xxx/CVE-2026-94623.json
Linked Threat: CVE-2026-94623 — vLLM through 0.29.0 Denial of Service via NIXL Multi-Prompt Assertion Failure

NVD triage scoring NVD CVE 2.0

Layer NVD adds on top of the CNA's CVE record — published / last-modified timestamps, exploitability / impact subscores, and the FIRST.org EPSS probability that this CVE will be exploited in the wild in the next 30 days.

NVD published: 2026-09-21 22:17:01 UTC
NVD last modified: 2026-09-21 22:17:01 UTC
NVD CVSS v3.1: 7.5 / 10 HIGH source: disclosure@vulncheck.com
NVD CVSS vector: CVSS:3.1/AV:N/AC:L/PR:N/UI:N/S:U/C:N/I:N/A:H
Exploitability subscore: 3.9 / 10
Impact subscore: 3.6 / 10

European Union Vulnerability Database ENISA EUVD

ENISA's official EU repository for curated vulnerability intelligence. Carries a separate identifier (EUVD-YYYY-NNNN) and frequently exposes an earlier-published description + CVSS than NVD does.

EUVD ID: EUVD-2026-84217
Assigner: VulnCheck
Published: Sep 21, 2026, 10:04:12 PM
Updated: Sep 21, 2026, 10:04:12 PM
EUVD base score (CVSS 4.0): 8.7 / 10
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
EUVD-reported EPSS: 0.0000
Vendors: vllm-project
Products: vllm (0 ≤0.29.0)
Aliases: GHSA-g3cp-v4cp-9xfq

ENISA 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.

EUVD references (4)

Affected products (1)

Vendor	Product	Versions	Platforms
vllm-project	vllm	`0` (affected)	—

Vendor references (4)

References embedded in the original CVE record by the assigning CNA.

Pull Request #51505 issue-trackingpatch
https://github.com/vllm-project/vllm/blob/v0.29.0/vllm/distributed/kv_transfer/kv_connector/v1/nixl/base_worker.py#L2642-L2646 technical-description
https://github.com/vllm-project/vllm product
VulnCheck Advisory: vLLM through 0.29.0 Denial of Service via NIXL Multi-Prompt Assertion Failure third-party-advisory

Web references (0)

DuckDuckGo results ranked by threat-intel / vendor advisory domains. Generated by the 🔎 Find references (web) button above — same flow as the Remediations search.

No web references attached yet.

NVD-tagged references (4)

Reference list NVD curates from the CNA record, vendor advisories, and third-party reports. The tag chips below are NVD's analyst-assigned categories.

https://github.com/vllm-project/vllm disclosure@vulncheck.com
https://github.com/vllm-project/vllm/blob/v0.29.0/vllm/distributed/kv_transfer/kv_connector/v1/nixl/base_worker.py#L2642-L2646 disclosure@vulncheck.com
https://github.com/vllm-project/vllm/pull/51505 disclosure@vulncheck.com
https://www.vulncheck.com/advisories/vllm-through-0.29.0-denial-of-service-via-nixl-multi-prompt-assertion-failure disclosure@vulncheck.com

Remediations (10)

Remediations are stored against the linked Threat row; the list below is deduplicated across both pages.

July 2026 Critical Patch Update Released | security - Oracle Blogs

web:blogs.oracle.com

For more information about the Critical Patch Update program, see the security vulnerability remediation practices page located on the Oracle Trust Center.

2026-09-22 16:45 UTC
Microsoft Update Catalog

web:catalog.update.microsoft.com

Welcome to the Microsoft Update Catalog site. We want your feedback! Visit our newsgroup or send us an email to provide us with your thoughts and suggestions. To get started using the site, enter in your search terms in the Search box above or visit our FAQ for search tips. |Newsgroup|Send us your feedback

2026-09-22 16:45 UTC
Security Update Guide - Microsoft

web:msrc.microsoft.com

The Microsoft Security Response Center (MSRC) investigates all reports of security vulnerabilities affecting Microsoft products and services, and provides the information here as part of the ongoing effort to help you manage security risks and help keep your systems protected.

2026-09-22 16:45 UTC
Security Update Guide - Microsoft Security Response Center

web:msrc.microsoft.com

Security Update Guide - Microsoft Security Response Center

2026-09-22 16:45 UTC
Cisco Advance Notification for Publication of September 16, 2026 ...

web:sec.cloudapps.cisco.com

On September 16, 2026 , the Cisco Product Security Incident Response Team (PSIRT) published the advisories that are listed in the following tables. To remediate these vulnerabilities, Cisco strongly recommends that customers upgrade to the fixed software that is indicated in the advisories. For more information about changes in Cisco PSIRT vulnerability disclosure, see Strengthening the ...

2026-09-22 16:45 UTC
Microsoft Patch Tracker (September 2026): Exploit-Ranked | Senserva

web:senserva.com

Every Microsoft security patch (KB) and the CVEs it fixes, with severity, CVSS, and CISA KEV status. Cross-linked to the CVE reference.

2026-09-22 16:45 UTC
Patch Roll-up for CPR9 SRx - support.rockwellautomation.com

web:support.rockwellautomation.com

The roll-up uses specific check files to confirm which product is installed. The roll-up will only install patch files provided these files already exist on the target computer, unless a new binary file is being introduced as part of a patch . Patch Install Follow the link to download and extract the latest patch roll-up.

2026-09-22 16:45 UTC
SAP Security Patch Day - April 2026

web:support.sap.com

SAP security patch day bulletin This post shares the information on security notes that remediate vulnerabilities discovered in SAP products. SAP strongly recommends that the customer visits the support portal and applies patches on priority to protect their SAP landscape. On 14 th of April 2026 , SAP security patch day saw the release of 19 new security notes. There is 1 update to previously ...

2026-09-22 16:45 UTC
Oracle Critical Patch Update Advisory - July 2026

web:www.oracle.com

This Critical Patch Update contains 1448 new security patches across the product families listed below. Please note that a My Oracle Support (MOS) note summarizing the content of this Critical Patch Update and other Oracle Software Security Assurance activities is located at July 2026 Critical Patch Update: Executive Summary and Analysis.

2026-09-22 16:45 UTC
Oracle Critical Security Patch Update Advisory - June 2026

web:www.oracle.com

Additional CVEs addressed are: The patch for CVE - 2026 -34481 also addresses CVE - 2026 -34477, CVE - 2026 -34478, CVE - 2026 -34479, and CVE - 2026 -34480. Oracle Fusion Middleware Risk Matrix This Critical Security Patch Update contains 106 new security patches for Oracle Fusion Middleware. 53 of these vulnerabilities may be remotely exploitable without authentication, i.e., may be exploited over a ...

2026-09-22 16:45 UTC

AI Forensic Analysis

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Raw JSON

The full cvelistV5 record. Download as CVE-2026-94623.json.

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