CVE-2026-44551 CRITICAL

CVE-2026-44551: Open WebUI: LDAP Empty Password Authentication Bypass

Vendor Open-Webui
Product open-webui
Weakness CWE-287 · Improper authentication
Published May 15, 2026
Last update May 19, 2026

CVSS base score

9.1/10
Attack vector Network
Attack complexity Low
Privileges required None
User interaction None
Confidentiality High
Integrity High

CVSS vector

CVSS:3.1/AV:N/AC:L/PR:N/UI:N/S:U/C:H/I:H/A:N

What the vulnerability does

01Description

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.

Key dates

02Disclosure timeline

May 15, 2026 CVE published
May 19, 2026 Record updated