---
id: CVE-2026-109227
title: >-
  SGLang through 0.5.21 contains an unbounded memory allocation vulnerability in
  preprocess_video in qwen_vl.py that decodes frames at full source resolution
  before applying max_pixels limits
summary: >-
  SGLang through 0.5.21 contains an unbounded memory allocation vulnerability in
  preprocess_video in qwen_vl.py that decodes frames at full source resolution
  before applying max_pixels limits. Remote attackers can submit high-resolution
  vi…
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-770
published: '2026-10-12'
updated: '2026-10-12'
sourceUpdated: '2026-10-12T14:17:12.040'
source: NVD
sourceUrl: 'https://nvd.nist.gov/vuln/detail/CVE-2026-109227'
references:
  - url: 'https://github.com/sgl-project/sglang'
    label: disclosure@vulncheck.com
  - url: >-
      https://github.com/sgl-project/sglang/blob/v0.5.21/python/sglang/srt/multimodal/processors/qwen_vl.py#L267-L306
    label: disclosure@vulncheck.com
  - url: 'https://github.com/sgl-project/sglang/issues/43710'
    label: disclosure@vulncheck.com
  - url: >-
      https://www.vulncheck.com/advisories/sglang-through-0.5.21-memory-exhaustion-dos-via-qwen-vl-video-preprocessing
    label: disclosure@vulncheck.com
tags:
  - nvd
ingestedAt: '2026-10-12T14:50:34.122Z'
---

## Overview

SGLang through 0.5.21 contains an unbounded memory allocation vulnerability in preprocess_video in qwen_vl.py that decodes frames at full source resolution before applying max_pixels limits. Remote attackers can submit high-resolution videos to /v1/chat/completions on Qwen-VL deployments, and concurrent requests exhaust worker memory causing denial of service.

## Remediation

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