Open WebUI — Vulnerability (CVE-2026-54006)
Date: 2026-06
Affected: openwebui/open_webui
Attack vector: auth-bypass
Category: vulnerability-disclosure
Severity: Medium
CVE: CVE-2026-54006
CWE: CWE-639
CVSS: 4.3 (CVSS:3.1/AV:N/AC:L/PR:L/UI:N/S:U/C:N/I:L/A:N)

Open WebUI is a self-hosted artificial intelligence platform designed to operate entirely offline. Prior to 0.9.6, POST /api/v1/calendars/events/{event_id}/update validates that the caller has write access to the calendar the event currently belongs to, but does not validate the destination calendar_id supplied in the request body. The model layer then persists the new calendar_id unconditionally. A regular user-role account can therefore create an event in their own calendar and immediately move it into any other user's calendar whose ID they know — bypassing the authorization check that create_event correctly performs. This vulnerability is fixed in 0.9.6.


Mitigations:

Architectural layers (MAESTRO):