CVE-2026-109290

High

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.

SeverityHigh

CVSS8.7

Exploit probability—

ProductOpen-webui

PublishedOct 12, 2026

First seenOct 12, 2026

Weakness typeCWE-79Cross-site scripting (XSS)CWE-1021CWE-1021

How to fix

Update

open-webui open-webui0.11.4 or later

Vendor advisories

github.com/open-webui/open-webui/security/advisories/GHSA-f9xp-mfmq-x6cg

Affected products

Product	Affected versions	Fixed in
open-webui open-webui	0.11.1 ≤ v < 0.11.4	0.11.4

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