---
id: CVE-2026-94622
title: >-
  vLLM versions through 0.29.0 contain a denial of service vulnerability in the
  NIXL connector's metadata handling for prefill/decode disaggregated
  deployments
summary: >-
  vLLM versions through 0.29.0 contain a denial of service vulnerability in the
  NIXL connector's metadata handling for prefill/decode disaggregated
  deployments. Attackers can send requests with incomplete kv_transfer_params
  dictionary entr…
severity: high
cvss: 7.5
cvssVector: 'CVSS:3.1/AV:N/AC:L/PR:N/UI:N/S:U/C:N/I:N/A:H'
cwe:
  - CWE-248
vendor: vllm
product: vllm
affected:
  - vllm <= 0.29.0
published: '2026-09-21'
updated: '2026-09-29'
sourceUpdated: '2026-09-29T12:47:29.283'
source: NVD
sourceUrl: 'https://nvd.nist.gov/vuln/detail/CVE-2026-94622'
references:
  - url: 'https://github.com/vllm-project/vllm'
    label: disclosure@vulncheck.com
  - url: >-
      https://github.com/vllm-project/vllm/blob/v0.29.0/vllm/distributed/kv_transfer/kv_connector/v1/nixl/metadata.py#L294-L312
    label: disclosure@vulncheck.com
  - url: 'https://github.com/vllm-project/vllm/pull/54807'
    label: disclosure@vulncheck.com
  - url: >-
      https://www.vulncheck.com/advisories/vllm-through-0.29.0-denial-of-service-via-incomplete-nixl-kv-transfer-metadata
    label: disclosure@vulncheck.com
  - url: >-
      https://security.access.redhat.com/data/csaf/v2/vex/2026/cve-2026-94622.json
  - url: 'https://access.redhat.com/security/cve/CVE-2026-94622'
  - url: 'https://bugzilla.redhat.com/show_bug.cgi?id=2538247'
  - url: 'https://www.cve.org/CVERecord?id=CVE-2026-94622'
  - url: 'https://nvd.nist.gov/vuln/detail/CVE-2026-94622'
  - url: 'https://access.redhat.com/errata/RHSA-2026:84734'
tags:
  - nvd
  - cve.org
  - csaf
  - vex
  - red-hat
  - osv
  - pip
ssvc:
  exploitation: none
  automatable: 'yes'
  technicalImpact: partial
  timestamp: '2026-09-22T12:59:50.196633Z'
ingestedAt: '2026-09-21T22:54:37.971Z'
epss: 0.00627
epssPercentile: 0.49842
aliases:
  - PYSEC-2026-4004
ecosystem: pip
patched:
  - vllm 0.30.0
---

## Overview

vLLM versions through 0.29.0 contain a denial of service vulnerability in the NIXL connector's metadata handling for prefill/decode disaggregated deployments. Attackers can send requests with incomplete kv_transfer_params dictionary entries to trigger an uncaught KeyError in EngineCore scheduling, causing the decode engine to terminate and making all routed requests fail until manual restart.

## Affected

- `vllm <= 0.29.0`

## Remediation

Refer to the linked advisories for vendor-supplied fixes and affected version ranges.

## Vendor advisories

- **Red Hat VEX** · Important · affected: Red Hat AI Inference Server, Red Hat Enterprise Linux AI (RHEL AI) 3, Red Hat OpenShift AI (RHOAI) · no fix planned: Red Hat AI Inference Server, Red Hat Enterprise Linux AI (RHEL AI) 3, Red Hat OpenShift AI (RHOAI) · updated 2026-10-19 · [vex](https://security.access.redhat.com/data/csaf/v2/vex/2026/cve-2026-94622.json)
- **RHSA-2026:84734** · Red Hat · fixed in: Red Hat OpenShift AI 3.4 · released 2026-10-19 · [advisory](https://access.redhat.com/errata/RHSA-2026:84734)

## Package advisory (CVE-2026-94622)

Affected packages:

- `vllm < 0.30.0`

Patched in:

- `vllm 0.30.0`

Source: https://osv.dev/vulnerability/PYSEC-2026-4004