CVE-2026-54020

Name of the Vulnerable Software and Affected Versions Open WebUI versions prior to 0.11.0

Description An authenticated attacker can bypass URL validation to perform a DNS rebinding attack. The software validates hostnames by resolving them once to reject private, loopback, and link-local addresses, but the HTTP client resolves the hostname again at connection time. An attacker controlling the authoritative DNS can provide a public address during validation and an internal address during connection. This allows the server to issue requests to internal services, loopback-bound admin APIs, or cloud instance metadata (e.g., 169.254.169.254).

Technical details include the following affected components:

In the OAuth path, the server may also forward the OAuth access token as a Bearer header to the internal target. Responses are typically returned to the attacker as document content, described by a vision model, or base64-encoded into a profile picture.

Recommendations Update Open WebUI to version 0.11.0.