Vulnerability · Published May 15, 2026 · Assigned by GitHub_M
CVE-2026-45675Open WebUI: LDAP and OAuth First-User Race Condition Allows Multiple Admin Accounts
High 8.1
In plain English
A high-severity privilege mismanagement in open-webui from open-webui. There are no confirmed reports of exploitation so far. The chance it is exploited in the next 30 days is estimated at 0.4% (higher than 29% of all known vulnerabilities). Fixed versions are available - upgrade the affected package.
Official 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.
Affected packages & fixed versions
| Ecosystem | Package | Fixed in | Advisory |
|---|---|---|---|
| PyPI | open-webui | 0.9.0 | GHSA-h3ww-q6xx-w7x3 |
| PyPI | open-webui | 0.9.0 | PYSEC-2026-2730 |
Affected products (as reported)
| Vendor | Product | Versions |
|---|---|---|
| open-webui | open-webui | < 0.9.0 |
Weakness: CWE-269, CWE-362 · Vector: CVSS:3.1/AV:N/AC:H/PR:N/UI:N/S:U/C:H/I:H/A:H