Open WebUI before 0.11.4 contains a stored cross-site scripting vulnerability in MarkdownInlineTokens.svelte, which renders markdown link URLs into… (CVE-2026-109288)
Description
Open WebUI versions before 0.11.4 have a stored cross-site scripting (XSS) vulnerability in the MarkdownInlineTokens.svelte component. This flaw allows authenticated users to inject javascript: links into markdown-rendered chat messages. When other users click these malicious links, their JSON Web Tokens (JWTs) stored in local storage can be stolen, including those of administrators.
CVSS v3.1
Score 6.4medium
Affected software
pkg:github/open-webui/open-webuiRun on your own infrastructure? Check whether these packages are installed with threat-finder — our free open-source scanner.
Weaknesses
AI-Powered Analysis
Machine-generated threat intelligence
Technical Analysis
The vulnerability (CVE-2026-109288) exists in Open WebUI prior to version 0.11.4, specifically in the MarkdownInlineTokens.svelte file. The component renders markdown link URLs into anchor href attributes without validating the URL scheme, enabling authenticated users to embed javascript: scheme links. This stored XSS vulnerability can be exploited when victims click the malicious links, resulting in theft of their JWT tokens from local storage. The CVSS 3.1 score is 6.4 (High), reflecting network attack vector, high impact on confidentiality and integrity, but requiring low privileges and user interaction.
Potential Impact
Successful exploitation leads to theft of JWT tokens from local storage, compromising user sessions and potentially allowing attackers to impersonate victims, including administrators. This can lead to unauthorized access and control within the affected Open WebUI environment.
Mitigation Recommendations
A fix is available in Open WebUI version 0.11.4. Users should upgrade to version 0.11.4 or later to remediate this vulnerability. No other mitigation guidance is provided or necessary as the issue is resolved by the official patch.
Technical Details
- Gcve Source
- db.gcve.eu
- Osv Id
- GHSA-fhg2-q543-9wpq
- Osv Schema Version
- 1.4.0
- Aliases
- ["CVE-2026-109288"]
- Database Specific Severity
- HIGH
- Cvss Version
- 3.1
Threat ID: 6acd554b2cdf04f656da84d6
Added to database: 10/12/2026, 21:46:51 UTC
Last enriched: 10/12/2026, 21:54:49 UTC
Last updated: 10/13/2026, 03:28:23 UTC
Views: 2
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