CVE-2026-45665 HIGH

CVE-2026-45665: Open WebUI: Stored XSS in Banner Component via Improper Sanitization Order

Vendor Open-Webui
Product open-webui
Weakness CWE-79 · XSS
Published May 15, 2026
Last update May 18, 2026

CVSS base score

8.1/10
Attack vector Network
Attack complexity Low
Privileges required High
User interaction Required
Confidentiality High
Integrity High

CVSS vector

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

What the vulnerability does

01Description

Open WebUI is a self-hosted artificial intelligence platform designed to operate entirely offline. Prior to 0.8.0, a Stored Cross-Site Scripting (XSS) vulnerability exists in the Banner component due to an improper sanitization order (specifically, DOMPurify is executed before the marked library). This vulnerability allows a compromised or malicious administrator to plant a malicious payload in the global banner. Crucially, this vector enables Privilege Escalation, as the malicious banner is rendered for all users, including the Super Admin (Primary Admin). Consequently, the payload successfully bypasses the existing security mechanism. An attacker can leverage this to steal the Super Admin's session token This vulnerability is fixed in 0.8.0.

Key dates

02Disclosure timeline

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

Related vulnerabilities

04Related CVE