CVE-2026-44558: Openwebui Open Webui

Medium severity, CVSS 5.4. 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 0.9.0, the channel router does not call filter_allowed_access_grants on either create or update paths. A non-admin user who can create group channels (or who owns a channel) can submit arbitrary access grants — including public wildcard grants — and those grants are stored verbatim, bypassing the admin's permission framework. This vulnerability is fixed in 0.9.0.

Affected products

• Openwebui Open Webui: before 0.9.0 (fixed in 0.9.0)

Published 2026-05-15. Last modified 2026-06-17.