CVE-2026-45385

Open WebUI: An IDOR vulnerability exists in the update_message_by_id API endpoint

State: Published
Severity: 4.3 Medium
Published: May 15, 2026
Updated: May 18, 2026
Reserved: May 12, 2026

Description

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.

Scores

CVSS	Score	Vector	Source
3.1	4.3 Medium	CVSS:3.1/AV:N/AC:L/PR:L/UI:N/S:U/C:N/I:L/A:N	GitHub_M

Weaknesses

CWE-639 Authorization Bypass Through User-Controlled Key

Affected Products

Product	Versions
open-webuiopen-webui	< 0.9.5Affected

References

https://github.com/open-webui/open-webui/security/advisories/GHSA-wwhq-cx22-f7vv

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