Cross-site scripting in Open WebUI - #VU131115
Published: May 12, 2026
Vulnerability identifier: #VU131115
CSH Severity: Low
CVSS v4.0: CVSS:4.0/AV:N/AC:L/AT:N/PR:H/UI:P/VC:N/VI:N/VA:N/SC:L/SI:L/SA:N/E:U/U:Clear
CVE-ID: N/A
CWE-ID: CWE-79
Exploitation vector: Remote access
Exploit availability:
No public exploit available
Vendor: Open WebUI
Affected software:
Open WebUI
Open WebUI
Detailed vulnerability description
The vulnerability allows a remote user to execute arbitrary script in a victim's browser and disclose sensitive information.
The vulnerability exists due to cross-site scripting in the Banner component in src/lib/components/common/Banner.svelte when rendering stored banner content after sanitizing input before parsing it with marked. A remote privileged user can store a specially crafted banner payload to execute arbitrary script in a victim's browser and disclose sensitive information.
User interaction is required, and the malicious banner is rendered for other users including the primary administrator.
Remediation
Install security update from vendor's website.