# CVE-2026-34755: vLLM Affected by Denial of Service via Unbounded Frame Count in video/jpeg Base64 Processing

> Attackers can crash vLLM servers by sending requests with excessive base64-encoded JPEG frames, bypassing frame count limits.

- **Severity:** Medium 6.5 (`CVSS:3.1/AV:N/AC:L/PR:L/UI:N/S:U/C:N/I:N/A:H`)
- **Exploited in the wild:** Not known
- **Login needed:** Any signed-in user
- **Attackable:** Over the internet
- **Victim action needed:** Not needed
- **Fix available:** Yes
- **Published:** 6 Apr 2026
- **Updated:** 25 Aug 2026
- **Also known as:** GHSA-pq5c-rjhq-qp7p, PYSEC-2026-144

## What is CVE-2026-34755?

CVE-2026-34755 is a medium-severity denial of service vulnerability in Vllm Vllm, published on 6 Apr 2026. Any signed-in user can exploit it over the network, with no action from the victim.

### Official description

vLLM is an inference and serving engine for large language models (LLMs). From 0.7.0 to before 0.19.0, the VideoMediaIO.load_base64() method at vllm/multimodal/media/video.py splits video/jpeg data URLs by comma to extract individual JPEG frames, but does not enforce a frame count limit. The num_frames parameter (default: 32), which is enforced by the load_bytes() code path, is completely bypassed in the video/jpeg base64 path. An attacker can send a single API request containing thousands of comma-separated base64-encoded JPEG frames, causing the server to decode all frames into memory and crash with OOM. This vulnerability is fixed in 0.19.0.

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

## Which versions are affected by CVE-2026-34755?

3 open source packages ship an affected version, including vllm. It affects 1 product.


| Package | Ecosystem | Affected | Fixed in |
| --- | --- | --- | --- |
| `vllm` | PyPI | From 0.7.0 | 0.19.0 |
| `vllm` | PyPI | From 0.7.0 | 0.19.0 |
| `vllm` | PyPI | From 0.7.0 | 0.19.0 |

Products: Vllm Vllm.

## How do I fix CVE-2026-34755?

Upgrade vllm to 0.19.0 or later.

## Is CVE-2026-34755 being exploited?

There is no known exploitation of CVE-2026-34755 in the wild and no public exploit code.

## Other vulnerabilities in Vllm Vllm

- [CVE-2025-32444](https://insights.sbomify.com/CVE-2025-32444/): vLLM Vulnerable to Remote Code Execution via Mooncake Integration (critical 10.0)
- [CVE-2026-22778](https://insights.sbomify.com/CVE-2026-22778/): vLLM leaks a heap address when PIL throws an error (critical 9.8)
- [CVE-2025-47277](https://insights.sbomify.com/CVE-2025-47277/): vLLM Allows Remote Code Execution via PyNcclPipe Communication Service (critical 9.8)
- [CVE-2024-11041](https://insights.sbomify.com/CVE-2024-11041/): Remote Code Execution in vllm-project/vllm (critical 9.8)
- [CVE-2026-48746](https://insights.sbomify.com/CVE-2026-48746/): vLLM: OpenAI auth bypass (critical 9.1)

## Fix prompt for AI coding agents

```text
Check this codebase for CVE-2026-34755 and fix it if it is affected.

What it is: CVE-2026-34755 is a medium-severity denial of service vulnerability in Vllm Vllm, published on 6 Apr 2026. Any signed-in user can exploit it over the network, with no action from the victim.
Exploitation: There is no known exploitation of CVE-2026-34755 in the wild and no public exploit code.

Affected packages and fixed versions:
- vllm (PyPI): affected from 0.7.0; fixed in 0.19.0
- vllm (PyPI): affected from 0.7.0; fixed in 0.19.0
- vllm (PyPI): affected from 0.7.0; fixed in 0.19.0

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-2026-34755/ (Markdown: https://insights.sbomify.com/CVE-2026-34755/index.md)
```

## Sources

- CVE record: https://www.cve.org/CVERecord?id=CVE-2026-34755
- NVD: https://nvd.nist.gov/vuln/detail/CVE-2026-34755
- OSV: https://osv.dev/vulnerability/CVE-2026-34755

---
From sbomify Insights: https://insights.sbomify.com/CVE-2026-34755/
Summaries are generated and may contain mistakes; the official description above is the record.