vLLM : DoS via unvalidated mm_processor_kwargs in multimodal image processors (Isaac, InternVL, H2OVL, etc.)
What fixes it
A fixed version on one release line is not the upgrade target for every line. Check your exact version and any vendor backports.
Description
Summary
API clients can supply arbitrary mm_processor_kwargs per request. vLLM forwards these values through the multimodal rendering and processing pipeline to Hugging Face and custom image/video processor constructors and calls. Resource-sensitive values such as image size, patch size, patch count, crop count, or frame count can therefore be controlled by a remote client.
For processors that upscale inputs, a single request can force an allocation large enough to terminate the API server or worker with an out-of-memory condition.
Affected Components
The per-request field was introduced in commit 041e29471671a3d43afedb6a749421d56ef4d3e7 and first shipped in v0.7.3. The generic forwarding path remains present in current main.
The Isaac path is a concrete high-amplification example:
ChatCompletionRequest.mm_processor_kwargsOnlineRendererrequest extrasMMProcessorInputs.hf_processor_mm_kwargsBaseMultiModalProcessor.info.get_hf_processor(**hf_processor_mm_kwargs)IsaacProcessingInfo.get_image_processor(**kwargs)IsaacImageProcessor(**kwargs)process_vision_for_patches()
Equivalent constructor forwarding exists in InternVL-derived processors, H2OVL, Step3VL, NemotronVL, and other multimodal processors. The issue is at the shared remote-input boundary and is not limited to a fixed model list.
Impact
- Availability: one request can exhaust CPU or GPU memory and terminate a
shared service process.
- Scope: all users of the affected service instance lose availability.
- Authentication: vLLM's API key is optional, so deployments without an
external authentication layer are remotely reachable without privileges.
Remediation
Reject non-empty per-request mm_processor_kwargs at every API-server request schema by default. Operators serving only trusted clients can explicitly opt in to the existing override behavior. Server-level --mm-processor-kwargs and offline LLM overrides remain available.
This shared boundary covers current and future multimodal processors instead of maintaining a model-specific list or a denylist that can miss custom processor arguments.
A patch for this was merged here: https://github.com/vllm-project/vllm/pull/58830
Text from GitHub Advisory Database
Affected versions 3
- vllm, pip>= 0.7.3, < 0.31.0GitHub
- vllmaffected: 0.7.3 before 0.31.0CVE List
- vllmunaffected: 0.31.0CVE List
References 7
- github.com/vllm-project/vllm/commit/31f2e70cd3e403aaa471fb7fe3d33a7207aaf3ccFixvia GitHub
- github.com/vllm-project/vllm/releases/tag/v0.31.0Fixvia GitHub
- github.com/vllm-project/vllm/security/advisories/GHSA-gx7p-2j49-hfq4Advisoryvia CVE List
- vulncheck.com/advisories/vllm-0.7.3-before-0.31.0-dos-via-unvalidated-mm-processor-kwargsAdvisoryvia CVE List
- github.com/advisories/GHSA-gx7p-2j49-hfq4Advisoryvia GitHub
- nvd.nist.gov/vuln/detail/CVE-2026-114055Referencevia GitHub
- github.com/vllm-project/vllm/pull/58830Referencevia GitHub