gcdRadar
archive/Patch now/AIR-2026-1945
closedclosed 13 Nov 2026Patch now2 Disclosed vulnerabilityAI

CVE-2026-126397: vLLM quadratic CPU work vulnerability in Cohere2 Vision multimodal preprocessing

vLLM

vLLM forwards request-controlled max_patches values to the Hugging Face processor without an upper bound, causing quadratic CPU work. Remote clients can exhaust preprocessing workers and deny service to other users.

why this severityDisclosed vulnerability with a fix and no confirmed exploitation.

disclosed CVENo confirmed exploitation, so this record is tracked as a disclosed vulnerability and not counted as an incident. It moves into the counts if CISA or the vendor confirms exploitation. Why

CVSS
8.7
EPSS
0.01 · top 48% · 2026-11-13
EPSS scores by FIRST
fix status
Patched
affected
vLLM >= 0.10.1, < 0.31.0
fixed in
vLLM 0.31.0
first report
13 Nov 2026
last update
13 Nov 2026
CVE ids
CVE-2026-126397other records

What to do

Update vLLM to version 0.31.0 or later.

Timeline · 1

  1. 13 Nov 2026CVE-2026-126397: vLLM from 0.10.1 before 0.31.0 forwards a request-controlled mm_processor_kwargs.max_patches value to the Hugging Face processor…

Sources · 1

Advisories and databases

  1. 2026-11-13
    CVE-2026-126397: vLLM from 0.10.1 before 0.31.0 forwards a request-controlled mm_processor_kwargs.max_patches value to the Hugging Face processor…
    NVD · nvd.nist.gov/vuln/detail/CVE-2026-126397

Titles and links belong to their publishers. The summary above is written by gcdRadar in its own words; data is CC BY-SA 4.0.

Classification

lane
Patch now
AI role
Attack on AI
categories
Infrastructure vulnerability
severity
2 · Disclosed vulnerability
fix status
Patched
targets
Framework / tooling
owasp llm top 10
LLM03:2025 Supply Chain
mitre atlas
no technique for these categories
tags
denial-of-serviceresource-exhaustion
dates
happened 13 Nov 2026 · first reported 13 Nov 2026
origin
NVD
Vulnerability record from NVD / the GitHub Advisory Database. This product uses the NVD API but is not endorsed or certified by the NVD.
record
confidence 0.95 · created 2026-11-13 11:16Z · updated 2026-11-13 11:16Z

Lane, AI role, categories and severity come from the classifier; the OWASP and ATLAS rows are derived from the categories. How these are assigned

Copy a brief

This record as a short Markdown brief, for a ticket, a chat or a coding agent.

the brief as text
# CVE-2026-126397: vLLM quadratic CPU work vulnerability in Cohere2 Vision multimodal preprocessing

https://gcdradar.vercel.app/incidents/cve-2026-126397-vllm-quadratic-cpu-work-vulnerability-in-coh · AIR-2026-1945 · closed 2026-11-13

- Lane: Patch now
- Severity: 2 (Disclosed vulnerability): Disclosed vulnerability with a fix and no confirmed exploitation.
- Fix status: Patched
- First reported: 2026-11-13
- AI role: Attack on AI
- Products: vLLM
- CVE ids: CVE-2026-126397
- CVSS: 8.7

## Summary

vLLM forwards request-controlled max_patches values to the Hugging Face processor without an upper bound, causing quadratic CPU work. Remote clients can exhaust preprocessing workers and deny service to other users.

## What to do

Update vLLM to version 0.31.0 or later.

## Affected and fixed versions

- Affected: vLLM >= 0.10.1, < 0.31.0
- Fixed in: vLLM 0.31.0

## Latest updates

- 2026-11-13: CVE-2026-126397: vLLM from 0.10.1 before 0.31.0 forwards a request-controlled mm_processor_kwargs.max_patches value to the Hugging Face processor… (https://nvd.nist.gov/vuln/detail/CVE-2026-126397)

## Sources

- 2026-11-13 NVD: CVE-2026-126397: vLLM from 0.10.1 before 0.31.0 forwards a request-controlled mm_processor_kwargs.max_patches value to the Hugging Face processor… https://nvd.nist.gov/vuln/detail/CVE-2026-126397

Verify against the vendor's advisory before changing production. Data CC BY-SA 4.0, https://gcdradar.vercel.app.

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