Vulnerability · Published Oct 12, 2026 · Assigned by VulnCheck

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

High 8.7

In plain English

A high-severity cross-site scripting in open-webui from open-webui. Proof-of-concept exploit code is public. The chance it is exploited in the next 30 days is estimated at 0.3% (higher than 24% of all known vulnerabilities).

Severity (CVSS 3.1)8.7High

Exploit odds (30 days)0.3%top 75.6% of all CVEs

Exploited in the wildNo reportsCISA SSVC: poc

Attack toolingNoneno public tooling known

Official 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 (as reported)

Vendor	Product	Versions
open-webui	open-webui	0.11.1 – before 0.11.4

Weakness: CWE-79, CWE-1021 · Vector: CVSS:3.1/AV:N/AC:L/PR:L/UI:R/S:C/C:H/I:H/A:N

References

GitHub Security Advisory (GHSA-f9xp-mfmq-x6cg) vendor-advisory
VulnCheck Advisory: Open WebUI 0.11.1 before 0.11.4 Stored XSS via DOCX Preview third-party-advisory