CVE-2026-54020

Open WebUI is an extensible, feature-rich, and user-friendly self-hosted AI platform. Prior to 0.11.0, Open WebUI resolved a hostname during URL validation and rejected private, loopback, and link-local addresses, but the HTTP clients resolved the hostname again at connection time. An authenticated attacker who controlled authoritative DNS for a submitted hostname could answer with a public address during validation and an internal one during connection, reaching cloud metadata, loopback admin APIs, or internal services through URL ingest, chat image_url fetches, image editing, or OAuth profile-picture fetches, with most paths returning the response to the attacker and the OAuth path forwarding the OAuth access token. This issue is fixed in 0.11.0.

Score

CVSS 3.1 6.3 Medium

Status

Analyzed - security-advisories@github.com

Published

2026-08-04

Last modified

2026-08-05

Weaknesses

CWE-367, CWE-918

Affected products

• Open-webui (Open-webui)
• Open Webui (Openwebui)

References

• https://github.com/open-webui/open-webui/releases/tag/v0.11.0
• https://github.com/open-webui/open-webui/security/advisories/GHSA-h6x2-583h-x99r