Open WebUI — Xss (CVE-2026-44549)
Date: 2026-05
Affected: openwebui/open_webui
Attack vector: xss
Category: vulnerability-disclosure
Severity: High
CVE: CVE-2026-44549
CVE-2026-45314
CVE-2026-45315
CVE-2026-45316
CVE-2026-45317
CVE-2026-45318
CWE: CWE-20
CWE-352
CWE-434
CWE-646
CWE-79
CWE-863
CWE-87
CVSS: 7.3 (CVSS:3.1/AV:N/AC:L/PR:L/UI:R/S:U/C:H/I:H/A:N)

Open WebUI is a self-hosted artificial intelligence platform designed to operate entirely offline. Prior to 0.8.0, Excel file attachments are previewed in an unsafe way. A crafted XLSX file payload can be used to cause the sheetjs function sheet_to_html to embed an XSS payload into the generated HTML. This is subsequently added to the DOM unsanitized via @html causing the payload to trigger. This vulnerability is fixed in 0.8.0.


Mitigations:

Architectural layers (MAESTRO):