CVE-2026-54006: Openwebui Open Webui

Medium severity, CVSS 4.3. EPSS: 0.3% chance of exploitation in the next 30 days.

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.

Affected products

• Openwebui Open Webui: before 0.9.6 (fixed in 0.9.6)

Published 2026-06-23. Last modified 2026-06-25.