High severity · published Oct 12, 2026
CVE-2026-109290
Open WebUI 0.11.1 before 0.11.4 Stored XSS via DOCX Preview
8.7
CVSS
0.3%
EPSS
No
On KEV
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.
CVSS vector
CVSS:3.1/AV:N/AC:L/PR:L/UI:R/S:C/C:H/I:H/A:N
Attack vector
Network
Complexity
Low
Privileges
Low
User interaction
Required
Confidentiality
High
Integrity
High
Availability
None
Scope
Changed
Exploitation
Is it being used?
Exploit prediction (EPSS)0.3% · higher than 24% of CVEs
Exploited in the wildNo evidence yet
CISA KEVNot listed
Ransomware campaign useNot known
Affected products
Which versions
OP
open-webui · open-webui
0.11.1 before 0.11.4 · source: vendor
References
NVD
https://nvd.nist.gov/vuln/detail/CVE-2026-109290
CVE.org
https://www.cve.org/CVERecord?id=CVE-2026-109290
vendor-advisory
https://github.com/open-webui/open-webui/security/advisories/GHSA-f9xp-mfmq-x6cg
third-party-advisory
https://www.vulncheck.com/advisories/open-webui-0.11.1-before-0.11.4-stored-xss-via-docx-preview
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