CVE-2026-109288: Open WebUI before 0.11.4 Stored XSS via javascript: URLs in Markdown Links

Q: Which deployments are affected?

Open WebUI versions before 0.11.4 are affected. The provided information does not identify any configuration prerequisite.

Q: What access and interaction are required for exploitation?

An attacker must be an authenticated user who can place a crafted Markdown link in a shared chat. A victim must click the javascript: link for the payload to execute.

Q: What is the practical impact if an administrator clicks a malicious link?

The malicious script can steal the victim's JWT from local storage. This includes administrator tokens, potentially allowing an attacker to act using the stolen token.

Published Oct 12, 2026

Updated

Open WebUI before 0.11.4 contains a stored cross-site scripting vulnerability in MarkdownInlineTokens.svelte, which renders markdown link URLs into anchor hrefs without validating their scheme. Authenticated users can embed javascript: links in shared chats that, when clicked by a victim, steal the victim's JWT from local storage, including admins' tokens.

Affected Software

1 affected component

Open WebUI Open WebUI<0.11.4

Event History

Oct 12, 2026

CVE Published

via MITRE·04:04 PM

Data Sourced

via MITRE·04:04 PM

DescriptionSeverityWeakness

Data Sourced

via NVD·05:17 PM

DescriptionSeverityWeakness

Event

via NVD·06:11 PM

Frequently Asked Questions

Which deployments are affected?

Open WebUI versions before 0.11.4 are affected. The provided information does not identify any configuration prerequisite.

What access and interaction are required for exploitation?

An attacker must be an authenticated user who can place a crafted Markdown link in a shared chat. A victim must click the javascript: link for the payload to execute.

What is the practical impact if an administrator clicks a malicious link?

The malicious script can steal the victim's JWT from local storage. This includes administrator tokens, potentially allowing an attacker to act using the stolen token.

CVE-2026-109288: Open WebUI before 0.11.4 Stored XSS via javascript: URLs in Markdown Links

Affected Software

Event History

Frequently Asked Questions

Which deployments are affected?

What access and interaction are required for exploitation?

What is the practical impact if an administrator clicks a malicious link?

Company

Resources

Contact

Frequently Asked Questions

Which deployments are affected?

What access and interaction are required for exploitation?

What is the practical impact if an administrator clicks a malicious link?