CVE-2026-45401

Open WebUI redirects bypass internal-address restrictions

Open WebUI project · Open WebUI

First documented disclosure · Review checkpoint

Summary

Authenticated users could make web or image retrieval follow redirects into private network resources.

Severity and exploitation evidence

High · 8.5/10 · CVSS 3.1. Severity source.

Exploitation not established: The reviewed sources do not establish malicious exploitation. A published proof of concept is not evidence of a customer compromise.

Technical severity is not a measure of observed attacks or of risk to your deployment. Attempts, demonstrations, and successful compromise retain the qualifications in the source.

How the weakness works

Initial URL validation was not repeated for redirect targets in several fetch paths.

Conditions required

An authenticated user and a reachable URL returning a redirect.

Potential impact

Disclosure of internal HTTP responses, including reachable metadata or administration services.

Affected versions and configurations

Before 0.9.5.

Fix and mitigation status

0.9.5.

Practical next steps

Upgrade and constrain retrieval egress; validate each redirect destination.

Operating lesson

Network access controls must survive redirects across every retrieval helper.

Evidence and limits

May 10 is upstream disclosure; May 15 is CVE publication. Exposure depends on services reachable from the WebUI server; not every metadata service yields credentials.

Sources