CVE-2026-44551 open-webui CVE debrief

Who should care

Administrators and security teams running self-hosted Open WebUI deployments that use LDAP authentication, especially where LDAP server behavior may accept empty-password binds.

Technical summary

The issue is described as a missing validation step in the LDAP authentication endpoint: the submitted password was accepted as-is because the LdapForm Pydantic model allowed password:str without a minimum length constraint. An empty string could therefore reach Connection.bind(), and if the LDAP server accepted the bind, Open WebUI would create an authenticated session for the target user. NVD lists the vulnerability as affecting open_webui versions before 0.9.0 and maps it to CWE-287.

Defensive priority

High. This is an unauthenticated network-reachable authentication issue with potential impact to confidentiality and integrity, and NVD rates it CVSS 9.1/Critical.

Recommended defensive actions

• Upgrade Open WebUI to version 0.9.0 or later.
• If LDAP authentication is enabled, review the deployment’s login flow and confirm empty passwords are rejected before bind attempts.
• Check authentication and session logs for unexpected successful logins or session creation events tied to LDAP users.
• If practical in your environment, verify LDAP server policy does not permit empty-password Simple Bind behavior for this application path.
• Revoke or rotate active sessions after remediation if you have reason to suspect misuse.

Evidence notes

All substantive findings here come from the supplied CVE description and NVD metadata. The record states that Open WebUI prior to 0.9.0 lacked non-empty password validation in its LDAP authentication endpoint, that an empty password could pass validation, that Connection.bind() could succeed on vulnerable LDAP servers, and that a full session token could then be issued. NVD metadata also marks the issue as analyzed, assigns CVSS 3.1 vector AV:N/AC:L/PR:N/UI:N/S:U/C:H/I:H/A:N, lists CWE-287, and indicates the vulnerable version range ends before 0.9.0.

Sources and references

Methodology and review provenance

AI-assisted synthesis based on stored public vulnerability evidence. System validation, approval state, and publication status do not by themselves establish human review of this revision. PatchSiren helps prioritize defensive review and does not prove exposure or remediation on any system.