CVE-2026-109291
Received Received - Intake

Cross-Site Scripting in Open WebUI via Malicious Citation URLs

Publication date: 2026-10-12

Last updated on: 2026-10-12

Assigner: VulnCheck

Description
Open WebUI from 0.6.33 before 0.11.4 contains a cross-site scripting vulnerability that allows authenticated users to execute script in victims' sessions by storing javascript: URLs in citation embed_url fields. Attackers can share a crafted chat whose citation, when clicked, is passed to window.open, letting them steal localStorage.token and act as the victim.

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Meta Information

Published
2026-10-12
Last Modified
2026-10-12
Generated
2026-10-12
AI Q&A
2026-10-12
EPSS Evaluated
N/A
NVD
CVE-2026-109291
EUVD
EUVD-2026-97593

Affected Vendors & Products

Showing 1 associated CPE
Vendor Product Version / Range
open-webui open-webui 0.6.33

Helpful Resources

Exploitability

CWE
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KEV
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CWE ID Description
CWE-79 The product does not neutralize or incorrectly neutralizes user-controllable input before it is placed in output that is used as a web page that is served to other users.

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Executive Summary

This vulnerability is a cross-site scripting (XSS) flaw in Open WebUI versions before 0.11.4. Authenticated users can inject malicious JavaScript code by storing javascript: URLs in citation embed_url fields. When a victim clicks the crafted citation, it triggers window.open, allowing attackers to steal the victim's localStorage.token and impersonate them.

Detection Guidance

Check Open WebUI versions below 0.11.4 for vulnerability. Inspect chat citations for javascript: URLs in embed_url fields. Monitor network traffic for suspicious window.open calls or token exfiltration attempts.

Impact Analysis

If you use Open WebUI versions before 0.11.4, an attacker could gain access to your account by stealing your session token. This could lead to unauthorized actions performed on your behalf, data theft, or further compromise of your system depending on the permissions of your account.

Compliance Impact

This vulnerability could lead to unauthorized access to sensitive data, violating GDPR's data protection principles and HIPAA's security requirements. Organizations may face compliance violations, legal penalties, and reputational damage if user data is compromised through this flaw.

Mitigation Strategies

Upgrade Open WebUI to version 0.11.4 or later. Review and remove any suspicious citations containing javascript: URLs. Implement input validation to block javascript: URLs in citation fields.

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