CVE-2026-45675 Details
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.
A race condition vulnerability has been identified in Open WebUI's LDAP and OAuth authentication flows, prior to version 0.9.0. This vulnerability arises from a Time-of-Check-Time-of-Use (TOCTOU) issue in the first-user admin role assignment process. The regular signup handler was patched to prevent this race condition, but the LDAP and OAuth paths were not updated, allowing multiple users to be concurrently assigned admin roles on a fresh instance with no existing users.
Users should update to Open WebUI version 0.9.0 or later, where this vulnerability has been fixed. Instructions for updating can be found in the Open WebUI repository.
Metrics
CVSS 4.0 Severity and Vector Strings:
No CVSS 4.0 data is available for this CVE.
CVSS 3.x Severity and Vector Strings:
No data available for CVSS Version 2.0 on this CVE.
CISA-ADP
Assessed May 19, 2026References to Advisories, Solutions, and Tools
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| URL | Source(s) | Tag(s) |
|---|---|---|
| https://github.com/open-webui/open-webui/commit/96a0b3239b1aadb23fc359bf10849c9ba12fd6ec | [email protected] | Patch |
| https://github.com/open-webui/open-webui/pull/23626 | [email protected] | Issue Tracking |
| https://github.com/open-webui/open-webui/security/advisories/GHSA-h3ww-q6xx-w7x3 | [email protected] | ExploitMitigationVendor Advisory |
Weakness Enumeration
| CWE-ID | CWE Name | Source |
|---|---|---|
| CWE-269 | Improper Privilege Management | [email protected] |
| CWE-362 | Concurrent Execution using Shared Resource with Improper Synchronization ('Race Condition') | [email protected] |
Affected Products
| Product | Versions |
|---|---|
| openwebui open webui | < 0.9.0 |
CPE
Remediation
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Change History
7 change records found show changes
| Date | Action | Recorded By |
|---|---|---|
| Jun 18, 2026 | CVE Modified | [email protected] |
| Jun 17, 2026 | CVE Modified | [email protected] |
| Jun 17, 2026 | CVE Modified | CISA-ADP |
| May 19, 2026 | CVE Modified | CISA-ADP |
| May 19, 2026 | Initial Analysis | [email protected] |
| May 15, 2026 | CVE Modified | CISA-ADP |
| May 15, 2026 | New CVE Received | [email protected] |