# CVE-2026-109227: SGLang through 0.5.21 Memory Exhaustion DoS via Qwen-VL Video Preprocessing

> Remote attackers can cause denial of service in SGLang Qwen-VL deployments by submitting high-resolution videos that trigger unbounded memory allocation.

- **Severity:** High 8.7 (`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`)
- **Exploited in the wild:** Not known
- **Login needed:** Not needed
- **Attackable:** Over the internet
- **Victim action needed:** Not needed
- **Fix available:** No
- **Published:** 12 Oct 2026
- **Updated:** 18 Oct 2026
- **Also known as:** GHSA-6h2g-h3jf-2prp

## What is CVE-2026-109227?

CVE-2026-109227 is a high-severity denial of service vulnerability in sgl-project sglang, published on 12 Oct 2026. An attacker can exploit it over the internet without logging in, with no action from the victim.

### Official description

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.

Weakness: CWE-770 (Allocation of Resources Without Limits or Throttling)

## Which versions are affected by CVE-2026-109227?


## How do I fix CVE-2026-109227?

No fix has been published for CVE-2026-109227 yet. Limit exposure of the affected software until one is available.

## Is CVE-2026-109227 being exploited?

It is not confirmed as exploited in the wild, but public exploit code for CVE-2026-109227 exists.

## Fix prompt for AI coding agents

```text
Check this codebase for CVE-2026-109227 and fix it if it is affected.

What it is: CVE-2026-109227 is a high-severity denial of service vulnerability in sgl-project sglang, published on 12 Oct 2026. An attacker can exploit it over the internet without logging in, with no action from the victim.
Exploitation: It is not confirmed as exploited in the wild, but public exploit code for CVE-2026-109227 exists.

Affected product: sgl-project sglang. No package-level version data is available, so check the vendor advisory linked from the reference page.

Task:
1. Search the dependency manifests and lockfiles (for example package.json, package-lock.json, requirements.txt, poetry.lock, uv.lock, pom.xml, build.gradle, go.mod, Cargo.lock, Gemfile.lock) and any Dockerfiles for the affected packages, including transitive dependencies.
2. If an affected version is in use, upgrade it to the fixed version for its release line with the project's package manager, so the lockfile is regenerated. Prefer the smallest upgrade that fixes it.
3. If there is no fix, or the upgrade would break the build, do not guess: explain the risk and the safest workaround instead.
4. Run the tests and summarise what changed and why.
5. If nothing in the project is affected, say so and change nothing.

Reference: https://insights.sbomify.com/CVE-2026-109227/ (Markdown: https://insights.sbomify.com/CVE-2026-109227/index.md)
```

## Sources

- CVE record: https://www.cve.org/CVERecord?id=CVE-2026-109227
- NVD: https://nvd.nist.gov/vuln/detail/CVE-2026-109227
- OSV: https://osv.dev/vulnerability/CVE-2026-109227

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From sbomify Insights: https://insights.sbomify.com/CVE-2026-109227/
Summaries are generated and may contain mistakes; the official description above is the record.