CVE-2026-45675
High
Description
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.
SeverityHigh
CVSS8.1
Exploit probability—
ProductOpenwebui Open Webui
PublishedMay 15, 2026
First seenMay 15, 2026
How to fix
Update
- openwebui open_webui0.9.0 or later
- open-webui0.9.0 or later
Affected products
| Product | Affected versions | Fixed in |
|---|---|---|
| openwebui open_webui | v < 0.9.0 | 0.9.0 |
| open-webuiPyPI | v < 0.9.0 | 0.9.0 |
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