SB2026040408 - Multiple vulnerabilities in vLLM

Description

This security bulletin contains information about 3 secuirty vulnerabilities.

1) Server-Side Request Forgery (SSRF) (CVE-ID: CVE-2026-34753)

The vulnerability allows a remote user to make arbitrary HTTP requests from the server and disclose sensitive information.

The vulnerability exists due to server-side request forgery (SSRF) in download_bytes_from_url when processing batch input JSON containing a user-controlled file_url value. A remote user can supply a crafted file_url to make arbitrary HTTP requests from the server and disclose sensitive information.

The issue affects the batch runner path for BatchTranscriptionRequest and BatchTranslationRequest and may also impact availability by targeting reachable internal services.

2) Improper input validation (CVE-ID: CVE-2026-34756)

The vulnerability allows a remote user to cause a denial of service.

The vulnerability exists due to improper input validation in the OpenAI-compatible API server request handling for the n parameter when processing HTTP requests. A remote user can send a single HTTP request with an excessively large n value to cause a denial of service.

This issue affects the ChatCompletionRequest and CompletionRequest models and can block the Python asyncio event loop while triggering out-of-memory crashes by allocating large numbers of request object copies before scheduling.

3) Allocation of Resources Without Limits or Throttling (CVE-ID: CVE-2026-34755)

The vulnerability allows a remote user to cause a denial of service.

The vulnerability exists due to allocation of resources without limits or throttling in the VideoMediaIO.load_base64() method when processing video/jpeg base64 data URLs. A remote user can send a specially crafted request containing thousands of comma-separated base64-encoded JPEG frames to cause a denial of service.

The video/jpeg base64 code path bypasses the num_frames limit enforced by the load_bytes() path, causing all supplied frames to be decoded into memory and potentially crashing the server with an out-of-memory condition.

Remediation

Install update from vendor's website.

References

• https://github.com/vllm-project/vllm/security/advisories/GHSA-pf3h-qjgv-vcpr
• https://github.com/advisories/GHSA-pf3h-qjgv-vcpr
• https://github.com/vllm-project/vllm/security/advisories/GHSA-3mwp-wvh9-7528
• https://github.com/vllm-project/vllm/security/advisories/GHSA-pq5c-rjhq-qp7p