CVE-2026-45675CWE-269CWE-362

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

High · published May 15, 2026

CVSS v3.1
8.1
EPSS
1%
Percentile
42.3
In the wild
Unconfirmed
What it is

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.

The record
Technical detail
CVSS v3.1
8.1 · HIGH
Vector
CVSS:3.1/AV:N/AC:H/PR:N/UI:N/S:U/C:H/I:H/A:H
CVSS v4.0
Not supplied
EPSS
0.00505 · 42.3th percentile
Weaknesses
CWE-269 · Improper Privilege Management; CWE-362 · Concurrent Execution using Shared Resource with Improper Synchronization ('Race Condition')
Published
2026-05-15T19:12Z
EPSS history
Timeline
  • 15 MAY 19:12Z
    Open WebUI: LDAP and OAuth First-User Race Condition Allows Multiple Admin Accounts
    cvelistv5