Open WebUI from 0.11.1 before 0.11.4 contains a stored cross-site scripting vulnerability in DocxPreview.svelte that allows authenticated users to… (CVE-2026-109290)
Description
Open WebUI versions from 0.11.1 up to but not including 0.11.4 contain a stored cross-site scripting (XSS) vulnerability in the DocxPreview.svelte component. This flaw allows authenticated users to execute arbitrary scripts by uploading specially crafted DOCX files. Exploitation can lead to theft of a previewing administrator's session token from local storage, enabling instance takeover.
CVSS v3.1
Score 7.3high
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
A stored cross-site scripting vulnerability exists in Open WebUI versions 0.11.1 before 0.11.4 within the DocxPreview.svelte component. Authenticated users can exploit this by uploading DOCX attachments containing malicious OOXML altChunk HTML parts or script-scheme hyperlinks. Successful exploitation allows execution of arbitrary scripts in the context of an administrator previewing the document, potentially stealing session tokens from local storage and taking over the instance.
Potential Impact
The vulnerability allows an authenticated attacker to execute arbitrary scripts in the administrator's browser session, leading to theft of session tokens and full instance takeover. This compromises confidentiality and integrity of the affected system. The CVSS v3.1 score is 7.3 (High), reflecting network attack vector, low attack complexity, required privileges, user interaction, and high impact on confidentiality and integrity.
Mitigation Recommendations
No official patch or fix is currently documented. Patch status is not yet confirmed — check the vendor advisory for current remediation guidance. Until a fix is available, restrict DOCX file uploads to trusted users only and consider disabling the preview feature for DOCX files to reduce risk.
Technical Details
- Gcve Source
- db.gcve.eu
- Osv Id
- GHSA-39h3-jjqw-8pch
- Osv Schema Version
- 1.4.0
- Aliases
- ["CVE-2026-109290"]
- Database Specific Severity
- HIGH
- Cvss Version
- 3.1
Threat ID: 6acd554b2cdf04f656da84d9
Added to database: 10/12/2026, 21:46:51 UTC
Last enriched: 10/12/2026, 21:54:59 UTC
Last updated: 10/13/2026, 03:28:19 UTC
Views: 2
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