vLLM multimodal image processor fails to validate mm_processor_kwargs, causing denial-of-service vulnerability (involving Isaac, InternVL, H2OVL, etc.)

vLLM released a security advisory: its multimodal image processor does not validate mm_processor_kwargs in requests, allowing remote clients to trigger memory exhaustion and cause denial of service. The vulnerability ID is CVE-2026-114055, and it has been fixed in 0.31.0. API clients can pass arbitrary mm_processor_kwargs in each request, which are forwarded through the multimodal processing pipeline to the constructors of Hugging Face and custom image/video processors; resource-sensitive parameters such as image size, patch size, number of patches, number of crops, or number of frames can thus be controlled remotely. For processors that amplify input, a single request can force excessive memory allocation, causing the API server or worker to exit due to out-of-memory (OOM). Affected versions are 0.7.3 and above, and before 0.31.0.