vLLM Vulnerable to Remote DoS via Special-Token Placeholders

Exploitation

No confirmed exploitation recorded. Patch Next marks exploitation only from CISA KEV.

CVSS

6.5 · CVSS:3.1/AV:N/AC:L/PR:L/UI:N/S:U/C:N/I:N/A:H

EPSS

• CVE-2026-44222: 0.41% estimated exploitation activity in the next 30 days; percentile 35.74 (FIRST EPSS, 2026-11-03). This is a model estimate, not proof of exploitation or customer exposure.

As published by the source; long descriptions are shortened.

Summary This report explains a Token Injection vulnerability in vLLM’s multimodal processing. Unauthenticated, text-only prompts that spell special tokens are interpreted as control. Image and video placeholder sequences supplied without matching data cause vLLM to index into empty grids during input-position computation, raising an unhandled IndexError and terminating the worker or degrading availability. Multimodal paths that rely on imagegridthw/videogridthw are affected. Severity: High (remote DoS). Reproduced on vLLM 0.10.0 with Qwen2.5-VL. Details - Affected component: multimodal input position computation. - File/functions (paths are indicative): - vllm/modelexecutor/layers/rotaryembedding.py - getinputpositionstensor(...) - vlgetinputpositionstensor(...) - Failure mechanism: - The code counts detected vision tokens and then indexes videogridthw/imagegridthw accordingly. - When user input carries placeholder tokens but no actual multimodal payload, these grids are empty. The…

Published by the source

5 May 2026, 22:21 UTC

Last modified by the source

10 Sep 2026, 03:51 UTC

Source last checked

26 Oct 2026, 13:47 UTC

1. Revision 2 · amended · 26 Oct 2026

   Amended from ghsa record GHSA-hpv8-x276-m59f

2. Revision 1 · created · 24 Oct 2026

   Published from osv record GHSA-hpv8-x276-m59f

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# Patch Next advisory brief: CVE-2026-44222

Advisory: vLLM Vulnerable to Remote DoS via Special-Token Placeholders
IDs: CVE-2026-44222, GHSA-hpv8-x276-m59f
Record: https://patchnext.com/advisories/cve-2026-44222 (revision 2, source checked 26 Oct 2026, 13:47 UTC)
Inventory: none attached. This brief comes from a public page and does not say whether any deployment is affected.
Severity: Medium (CVSS 6.5)
Exploitation: no confirmed exploitation recorded. Patch Next confirms exploitation only from CISA KEV.
Vendor response: Vendor fix available; fixed versions by package: vllm 0.20.0. A vendor fix does not mean a deployment is fixed.

## Affected components
- PyPI vllm: affected >= 0.6.1, < 0.20.0; fixed in 0.20.0

## Suggested inspection (read-only)
- `python -m pip show vllm`: prints the installed version. Run with the environment that serves production active.

## Supported action
Upgrade each affected component to a fixed version on its release line. For a transitive dependency, upgrade the parent package or add an override or constraint, then regenerate the lockfile. Redeploy every environment that ran an affected version.

## Required regression checks
- Run the test suite and a production build.
- Exercise the features that depend on vllm.
- Repeat the inspection and confirm that only fixed versions remain installed.

## Rollback considerations
- Keep the previous lockfile and deployment artifact. Rolling back reinstates the vulnerable version, so apply any documented mitigation while you fix forward.

## Unresolved questions
- Which deployments run an affected version?
- Exploitation status can change. Check again before lowering the priority.
- Mark the work resolved only after the fixed version is verified in production.

## Sources
- Verified: https://osv.dev/vulnerability/GHSA-hpv8-x276-m59f (OSV record GHSA-hpv8-x276-m59f lists affected ranges: PyPI vllm >=0.6.1 <0.20.0 (fixed))
- Verified: https://github.com/advisories/GHSA-hpv8-x276-m59f (GitHub-reviewed advisory GHSA-hpv8-x276-m59f lists affected ranges: PyPI vllm >=0.6.1 <0.20.0)

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