Open WebUI — Vulnerability (CVE-2026-44551)
Date: 2026-05
Affected: openwebui/open_webui
Attack vector: auth-bypass
Category: vulnerability-disclosure
Severity: Critical
CVE: CVE-2026-44551
CWE: CWE-287
CVSS: 9.1 (CVSS:3.1/AV:N/AC:L/PR:N/UI:N/S:U/C:H/I:H/A:N)

Open WebUI is a self-hosted artificial intelligence platform designed to operate entirely offline. Prior to 0.9.0, the LDAP authentication endpoint does not validate that the submitted password is non-empty before performing a Simple Bind against the LDAP server. The LdapForm Pydantic model accepts password: str with no minimum length constraint, so an empty string passes validation. The subsequent Connection.bind() call succeeds on vulnerable LDAP servers, and the application issues a full session token for the target user. This vulnerability is fixed in 0.9.0.


Mitigations:

Architectural layers (MAESTRO):