What is CVE-2026-109290?

CVE-2026-109290 is a high-severity vulnerability in Open-Webui, classified under Cross-site Scripting. CVSS score: 7.3/10. Published 2026-10-12.

How severe is CVE-2026-109290?

High severity. CVSS v3 base score is 7.3 out of 10.

XSS in Open-Webui

CVE-2026-109290

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.

Vulnerability class: XSS (Cross-Site Scripting)

Published 2026-10-12.

CVSS v3 metric

CVSS v3 base score 7.3 (High). Vector: CVSS:3.1/AV:N/AC:L/PR:L/UI:R/S:U/C:H/I:H/A:N.

EPSS exploit prediction

No EPSS score from FIRST.org yet. New CVEs usually get one within a few days; no score means no signal yet, not low risk. How EPSS works.

Affected products

Open-Webui

Weakness classification (CWE)

CWE-79 — Cross-site Scripting

References

github.com/open-webui/open-webui/security/advisories/GHSA-f9xp-mfmq-x6cg (vendor-advisory)
www.vulncheck.com/advisories/open-webui-0.11.1-before-0.11.4-stored-xss-via-doc… (third-party-advisory)

Frequently asked questions

What is CVE-2026-109290?: CVE-2026-109290 is a high-severity vulnerability in Open-Webui, classified under Cross-site Scripting. CVSS score: 7.3/10. Published 2026-10-12.
How severe is CVE-2026-109290?: High severity. CVSS v3 base score is 7.3 out of 10.