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

Affected: vllm-project vllm, Red Hat AI Inference Server 3.2, Red Hat AI Inference Server 3.4, Red Hat Enterprise Linux AI 3.4, Red Hat AI Inference Server, Red Hat OpenShift AI (RHOAI)

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.

GHSA-pq5c-rjhq-qp7p — vLLM: Denial of Service via Unbounded Frame Count in video/jpeg Base64 Processing

Affected: PyPI: vllm

## Summary

The `VideoMediaIO.load_base64()` method at `vllm/multimodal/media/video.py:51-62` 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 at line 47-48, 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.

## Details

### Vulnerable code

```python # video.py:51-62 def load_base64(self, media_type: str, data: str) -> tuple[npt.NDArray, dict[str, Any]]: if media_type.lower() == "video/jpeg": load_frame = partial(self.image_io.load_base64, "image/jpeg") return np.stack( [np.asarray(load_frame(frame_data)) for frame_data in data.split(",")] # ^^^^^^^^^^ # Unbounded split — no frame count limit ), {} return self.load_bytes(base64.b64decode(data)) ```

The `load_bytes()` path (line 47-48) properly delegates to a video loader that respects `self.num_frames` (default 32). The `load_base64("video/jpeg", ...)` path bypasses this limit entirely — `data.split(",")` produces an unbounded list and every frame is decoded into a numpy array.

### video/jpeg is part of vLLM's public API

`video/jpeg` is a vLLM-specific MIME typ…

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

GHSA-pq5c-rjhq-qp7p — vLLM: Denial of Service via Unbounded Frame Count in video/jpeg Base64 Processing