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Vulnerability details

CVE-2026-45665

open-webui open-webui

Open WebUI: Stored XSS in Banner Component via Improper Sanitization Order

CVSS 3.1
8.1High

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.

CVSS scores

ScoreVersionSourceVector
8.1High 3.1 CVEProject cvelistV5 (CNA) (GitHub_M) CVSS:3.1/AV:N/AC:L/PR:H/UI:R/S:C/C:H/I:H/A:N

Affected products

VendorProductVersionsSource
open-webui open-webui < 0.8.0 CVEProject cvelistV5 (CNA)

References and advisories

1
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Details

Published
2026-05-16
Last updated
2026-05-18
State
Published
Assigner (CNA)
GitHub_M

Exploit prediction (EPSS)

0.33%
Probability of exploitation in 30 days
26.9%
Percentile (among all CVEs)

SSVC assessment (CISA)

Automatable
No
Exploitation
Proof of concept
Technical impact
Total

Weaknesses (CWE)

  • CWE-79
    Improper Neutralization of Input During Web Page Generation ('Cross-site Scripting')