CVE-2026-44551

published 2026-05-15

CVE-2026-44551: 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…

Priority P2 65 critical 9.1 CVSS 3.1

AV N AC L PR N UI N S U C H I H A N

EXPLOIT

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.

Affected

3 ranges

Vendor	Product	Version range	Fixed in
open-webui	open-webui	< 0.9.0	0.9.0
open-webui	open-webui	>= 0 < 0.9.0	0.9.0
openwebui	open_webui	< 0.9.0	0.9.0

Detection & IOCs extracted from sources · hover to see the quote

url /api/v1/auths/ldap↗

other shodan:http.title:"Open WebUI"↗

command {"user":"{{username}}","password":""}↗

• → Detect authentication bypass attempts by monitoring POST requests to /api/v1/auths/ldap with an empty password field in the JSON body. ↗
• → A successful exploit response will contain all three of the following strings in the body: '"token_type":', '{"id":', and '"name":', with HTTP status 200 — indicating a full session token was issued. ↗
• → Extract issued session tokens from successful exploit responses using the regex pattern '"token":"([^"]+)"' in the response body. ↗
• → Vulnerable Open WebUI instances can be discovered via Shodan using the query http.title:"Open WebUI". ↗

• · The vulnerability only triggers on LDAP servers that permit anonymous/unauthenticated Simple Bind with an empty password — not all LDAP server configurations are affected. ↗
• · The flaw exists because the LdapForm Pydantic model has no minimum length constraint on the password field, allowing an empty string to pass validation. Detection should focus on empty-password LDAP bind attempts rather than malformed requests. ↗
• · This vulnerability is only present in Open WebUI versions prior to 0.9.0; instances running 0.9.0 or later are not affected. ↗

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