Securaity Browse advisories
SA-26-100 High

Open WebUI: Prior to 0.8.0, a Stored Cross-Site Scripting (XSS) vulnerability exists in the Banner component…

Open WebUI

More for Open WebUI RSS feed for Open WebUI

Severity
High, CVSS 8.1
CVSS vector
CVSS:3.1/AV:N/AC:L/PR:H/UI:R/S:C/C:H/I:H/A:N
Record
CVE-2026-45665
Affects
Open WebUI
Known exploited
Not listed in the CISA Known Exploited Vulnerabilities catalog
Published
Record first published by the source
May 15, 2026
Source last modified
June 17, 2026

Description

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.

Description quoted from the NVD record.

Who is affected

Open WebUI is a chat interface: a self-hosted platform for using AI chat tools that can run entirely offline. This flaw affects all versions before 0.8.0 and sits in the banner feature, the announcement message shown to every user. An administrator account that is malicious or has been taken over can place harmful code in that banner. Because the banner appears for everyone, including the main administrator, the attacker can steal the main administrator's login session and gain their higher level of access. This flaw is rated High.

What to do

  1. The person who installed or runs Open WebUI for your organization should handle this.
  2. Check which version of Open WebUI you are running. Every version before 0.8.0 has this flaw.
  3. Update Open WebUI to version 0.8.0 or later, which fixes this flaw, then check that the new version is the one running.
  4. If an IT provider or vendor runs Open WebUI for you, send them this advisory and ask when the update will be done.

Analysis written from the source record as of June 17, 2026 and reviewed before publishing.

Sources

MORE ADVISORIES

See all