Vulnerability · Published May 15, 2026 · Assigned by GitHub_M

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

High 8.1

In plain English

A high-severity cross-site scripting in open-webui from open-webui. Proof-of-concept exploit code is public. The chance it is exploited in the next 30 days is estimated at 0.3% (higher than 27% of all known vulnerabilities). Fixed versions are available - upgrade the affected package.

Severity (CVSS 3.1)8.1High

Exploit odds (30 days)0.3%top 73.1% of all CVEs

Exploited in the wildNo reportsCISA SSVC: poc

Attack toolingNoneno public tooling known

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.

Affected packages & fixed versions

Ecosystem	Package	Fixed in	Advisory
npm	open-webui	0.8.0	GHSA-cqp4-qqvg-3787

Affected products (as reported)

Vendor	Product	Versions
open-webui	open-webui	< 0.8.0

Weakness: CWE-79 · Vector: CVSS:3.1/AV:N/AC:L/PR:H/UI:R/S:C/C:H/I:H/A:N

References

https://github.com/open-webui/open-webui/security/advisories/GHSA-cqp4-qqvg-3787 x_refsource_CONFIRM