CVE-2026-45318: Openwebui Open Webui

Medium severity, CVSS 5.4. EPSS: 0.2% chance of exploitation in the next 30 days.

Open WebUI is a self-hosted artificial intelligence platform designed to operate entirely offline. Prior to 0.9.3, his advisory tracks a regression of the original Excel-preview XSS (CVE-2026-44549). The same root cause — XLSX.utils.sheet_to_html() output rendered via {@html excelHtml} without DOMPurify — was reintroduced sometime after v0.8.0 and is exploitable again This vulnerability is fixed in 0.9.3.

Affected products

• Openwebui Open Webui: before 0.9.3 (fixed in 0.9.3)

Published 2026-05-15. Last modified 2026-06-17.