Authorization bypass through user-controlled key in Open WebUI - CVE-2026-45398
Published: May 11, 2026
Vulnerability identifier: #VU130956
CSH Severity: Low
CVSS v4: 7.7 [CVSS:4.0/AV:N/AC:L/AT:P/PR:L/UI:N/VC:H/VI:H/VA:H/SC:N/SI:N/SA:N]
CVE-ID: CVE-2026-45398
CWE-ID: CWE-639
Exploitation vector: Remote access
Exploit availability:
No public exploit available
Vulnerability details
The vulnerability allows a remote user to read and modify another user's private knowledge base content and cause a denial of service.
The vulnerability exists due to authorization bypass through user-controlled key in the retrieval API endpoints when handling knowledge base collection names supplied as raw UUIDs. A remote user can send specially crafted retrieval API requests using a target knowledge base UUID to read private content, inject attacker-controlled content, or overwrite the knowledge base.
Exploitation requires an authenticated non-admin account and knowledge of a target knowledge base UUID.
Affected software
Open WebUI
How to mitigate CVE-2026-45398
Install security update from vendor's website.
Open WebUI - update to 0.9.5