CVE-2026-109227
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.
Does this matter?
High impact if exploited, but EPSS currently rates exploitation as unlikely (0.51%). Schedule it in the normal patch cycle and watch for a rise in EPSS or a public exploit.
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.
- CVSS 4.0
- 8.7 HIGHCVSS:4.0/AV:N/AC:L/AT:N/PR:N/UI:N/VC:N/VI:N/VA:H/SC:N/SI:N/SA:N/E:X/CR:X/IR:X/AR:X/MAV:X/MAC:X/MAT:X/MPR:X/MUI:X/MVC:X/M
- EPSS
- 0.51% probability · 43th percentile
- Public exploits
- None in Exploit-DB
- CISA KEV
- Not listed
- Weakness
- CWE-770
- Source
- disclosure@vulncheck.com
EPSS moved from 0.4% on 13 October 2026 to 0.5% on 26 October 2026.
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
- https://github.com/sgl-project/sglang/issues/43710
Source: NVD record, EPSS from FIRST.org, KEV from CISA, exploits from Exploit-DB. Refreshed daily. Download this record as JSON.