CVE-2026-109227

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.

References

• https://github.com/sgl-project/sglang
• https://github.com/sgl-project/sglang/blob/v0.5.21/python/sglang/srt/multimodal/processors/qwen_vl.py#L267-L306
• https://github.com/sgl-project/sglang/issues/43710
• https://www.vulncheck.com/advisories/sglang-through-0.5.21-memory-exhaustion-dos-via-qwen-vl-video-preprocessing