GHSA-HCWP-82G6-8WXC Open WebUI has stored XSS via unsanitized Office/Excel/DOCX file preview rendering ({@html} without DOMPurify)

Related advisory This advisory tracks a regression of the original Excel-preview XSS that was publicly disclosed and patched under GHSA-jwf8-pv5p-vhmc patched in v0.8.0. The same root cause — XLSX.utils.sheettohtml output rendered via @html excelHtml without DOMPurify — was reintroduced sometime...

PT-2026-39266

Name of the Vulnerable Software and Affected Versions Open WebUI versions prior to 0.8.0 Description Excel file attachments are previewed unsafely. A crafted XLSX file can cause the sheet to html function to embed a Cross-Site Scripting XSS payload into the generated HTML. This content is then...