CVE-2026-126399: vLLM 0.19.0 before 0.31.0 Resource Exhaustion via Request-Level num_frames
vLLM from 0.19.0 before 0.31.0 contains a resource exhaustion vulnerability that allows inference clients to bypass the server frame limit by setting mediaiokwargs.video.numframes in chat completion requests. Attackers can supply numframes=-1 or a large value with many base64 JPEG frames, forcing VideoMediaIO to decode all frames and np.stack them, causing memory exhaustion.
Affected Software
Event History
Frequently Asked Questions
Who can exploit this issue?
An inference client with permission to submit chat completion requests can exploit it. The attack is network-reachable and requires low privileges, with no user interaction.
What request conditions trigger memory exhaustion?
The client supplies media_io_kwargs.video.num_frames as -1 or a large value and includes many base64-encoded JPEG frames. VideoMediaIO then decodes all supplied frames and stacks them in memory.
Are affected deployments protected by the server frame limit?
No. The request-level media_io_kwargs.video.num_frames setting can bypass the server frame limit in affected versions.
Which versions are affected?
vLLM versions from 0.19.0 before 0.31.0 are affected. Version 0.31.0 is not included in the affected range.