CVE-2026-45665 Open WebUI: Stored XSS in Banner Component via Improper Sanitization Order
A malicious administrator can inject scripts into the global banner to steal Super Admin session tokens, enabling privilege escalation.
- Exploited in the wild
- Not known
- Login needed
- An administrator
- Attackable
- Over the internet
- Victim action needed
- A user has to click or open something
- Fix
- Available
What is CVE-2026-45665?
CVE-2026-45665 is a high-severity cross-site scripting vulnerability in Openwebui Open Webui, published on 15 May 2026. An attacker needs administrator access to exploit it, and only if a user opens a file or follows a link.
Official 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.
Weakness: CWE-79
Which versions are affected by CVE-2026-45665?
2 open source packages ship an affected version, including open-webui. It affects 1 product.
| Package | Affected | Fixed in |
|---|---|---|
open-webui npm | All versions | 0.8.0 |
open-webui npm | All versions | 0.8.0 |
Products include Openwebui Open Webui.
How do I fix CVE-2026-45665?
Upgrade open-webui to 0.8.0 or later.
Escape output for the context it lands in and set a strict Content Security Policy. Upgrading the affected component is the real fix. More about Cross-site scripting.
Is CVE-2026-45665 being exploited?
It is not confirmed as exploited in the wild, but public exploit code for CVE-2026-45665 exists.
Other vulnerabilities in Openwebui Open Webui
- CVE-2026-44551 Open WebUI: LDAP Empty Password Authentication Bypass
- CVE-2026-56400 open-webui - Remote Code Execution via CORS Misconfiguration and Session Validation
- CVE-2024-8017 Cross-site Scripting (XSS) in open-webui/open-webui
- CVE-2026-45672 Open WebUI: Jupyter code execution works despite `ENABLE_CODE_EXECUTION=false` — feature gate bypassed
- CVE-2026-87995 Open WebUI: Same-origin XSS to account takeover via terminal port-preview iframe hardcoding allow-same-origin
Sources
Also known as GHSA-cqp4-qqvg-3787.