CVE-2026-45675

Open WebUI: LDAP and OAuth First-User Race Condition Allows Multiple Admin Accounts

Open WebUI is a self-hosted artificial intelligence platform designed to operate entirely offline. Prior to 0.9.0, the LDAP and OAuth authentication flows use a TOCTOU (Time-of-Check-Time-of-Use) pattern for first-user admin role assignment. The regular signup handler (signup_handler in auths.py, line 663) was explicitly patched to prevent this race with the comment "Insert with default role first to avoid TOCTOU race", but the LDAP and OAuth code paths were never updated with the same fix. This vulnerability is fixed in 0.9.0.

Affected

open-webui

CVSS v3.1 GITHUB

8.1 HIGHCVSS:3.1/AV:N/AC:H/PR:N/UI:N/S:U/C:H/I:H/A:H

EPSS

0.51% chance of exploitation in the next 30 days, 42nd percentile

Published

2026-05-15

Updated

2026-06-18

Proof-of-concept exploits (1)

• advisories/GHSA-h3ww-q6xx-w7x3

Security advisories

• open-webui/open-webui/security/advisories/GHSA-h3ww-q6xx-w7x3
• open-webui/open-webui/pull/23626

References

• CVE Record
• NVD entry