CVE-2026-34753

MEDIUM LAB

vLLM affected by Server-Side Request Forgery (SSRF) in `download_bytes_from_url `

Title source: cna
STIX 2.1

Exploitation Summary

EIP tracks 1 public exploit for CVE-2026-34753. PoCs published by Dhiaelhak-Rached.

AI-analyzed exploit summary This repository contains a functional proof-of-concept for CVE-2026-34753, demonstrating an SSRF vulnerability in vLLM's batch API. The exploit leverages the lack of URL validation in the `download_bytes_from_url` function to access internal services, such as a simulated AWS metadata service.

Description

vLLM is an inference and serving engine for large language models (LLMs). From 0.16.0 to before 0.19.0, a server-side request forgery (SSRF) vulnerability in download_bytes_from_url allows any actor who can control batch input JSON to make the vLLM batch runner issue arbitrary HTTP/HTTPS requests from the server, without any URL validation or domain restrictions. This can be used to target internal services (e.g. cloud metadata endpoints or internal HTTP APIs) reachable from the vLLM host. This vulnerability is fixed in 0.19.0.

Exploits (1)

github WORKING POC
by Dhiaelhak-Rached · pythonpoc
https://github.com/Dhiaelhak-Rached/CVE-2026-34753

This repository contains a functional proof-of-concept for CVE-2026-34753, demonstrating an SSRF vulnerability in vLLM's batch API. The exploit leverages the lack of URL validation in the `download_bytes_from_url` function to access internal services, such as a simulated AWS metadata service.

Classification
Working Poc 95%
Attack Type
Ssrf
Complexity
Moderate
Reliability
Reliable
Target: vLLM 0.18.x
No auth needed
Prerequisites: Docker environment · network connectivity between attacker and victim containers
devstral-2 · analyzed May 04, 2026 Full analysis →

References (1)

Core 1
Core References

Scores

CVSS v3 5.4
EPSS 0.0025
EPSS Percentile 15.5%
Attack Vector NETWORK
CVSS:3.1/AV:N/AC:L/PR:L/UI:N/S:U/C:L/I:N/A:L

CISA SSVC

Vulnrichment
Exploitation none
Automatable no
Technical Impact partial

Lab Environment

COMMUNITY
Community Lab
docker pull alpine/curl:latest

Details

CWE
CWE-918
Status published
Products (3)
pypi/vllm 0.16.0 - 0.19.0PyPI
vllm/vllm 0.16.0 - 0.19.0
vllm-project/vllm >= 0.16.0, < 0.19.0
Published Apr 06, 2026
Tracked Since Apr 06, 2026