What’s Vulnerable › Vulnerabilities

CVE-2026-109290: Open WebUI 0.11.1 before 0.11.4 Stored XSS via DOCX Preview

• Severity: high (CVSS 8.7 v3.1)
• Exploited in the wild: not listed in CISA KEV
• EPSS: 0.3% probability of exploitation in the next 30 days
• Public exploit or detection template: none known
• Published: 2026-10-12 · updated 2026-10-23
• Weakness: CWE-79

Description

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 execute script by uploading crafted DOCX attachments. Attackers can embed an OOXML altChunk HTML part or script-scheme hyperlink to steal a previewing administrator's session token from local storage and take over the instance.

Affected products

• open-webui: from 0.11.1 before 0.11.4 — fixed in 0.11.4

How to fix

Upgrade to a fixed version: open-webui 0.11.4. Check the vendor advisory for mitigations.

References

• https://github.com/open-webui/open-webui/security/advisories/GHSA-f9xp-mfmq-x6cg
• https://www.vulncheck.com/advisories/open-webui-0.11.1-before-0.11.4-stored-xss-via-docx-preview
• https://github.com/open-webui/open-webui/security/advisories/GHSA-f9xp-mfmq-x6cg

Get alerted when CVE-2026-109290 or the next vulnerability affects your stack