CVE-2026-45385 MEDIUM

CVE-2026-45385: Open WebUI: An IDOR vulnerability exists in the update_message_by_id API endpoint

Vendor Open-Webui
Product open-webui
Weakness CWE-639 · IDOR
Published May 15, 2026
Last update May 18, 2026

CVSS base score

4.3/10
Attack vector Network
Attack complexity Low
Privileges required Low
User interaction None
Confidentiality None
Integrity Low

CVSS vector

CVSS:3.1/AV:N/AC:L/PR:L/UI:N/S:U/C:N/I:L/A:N

What the vulnerability does

01Description

Open WebUI is a self-hosted artificial intelligence platform designed to operate entirely offline. Prior to 0.9.5, an IDOR vulnerability exists in the Channels feature of Open WebUI, allowing any channel member to modify messages sent by other members (including administrators) within the same channel. In the update_message_by_id function, for group or dm type channels, only the caller's membership in the channel is checked via the is_user_channel_member function, without verifying message ownership. This allows any channel member to modify messages sent by other members within the same channel. This vulnerability is fixed in 0.9.5.

Key dates

02Disclosure timeline

May 15, 2026 CVE published
May 18, 2026 Record updated