Open WebUI has stored XSS via unsanitized Office/Excel/DOCX file preview rendering ({@html} without DOMPurify) — CVE-2026-45318

Summary

## Related advisory This advisory tracks a regression of the original Excel-preview XSS that was publicly disclosed and patched under [GHSA-jwf8-pv5p-vhmc](https://github.com/open-webui/open-webui/security/advisories/GHSA-jwf8-pv5p-vhmc) (patched in v0.8.0). 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…

Product

pip: open-webui

What to do

General, cautious steps (verify details in the official source):

• Review exposure and plan remediation based on risk and environment.
• Identify affected product versions in your inventory and verify whether you are impacted.
• Apply vendor patches/updates or recommended mitigations as soon as available.
• Read the official advisory for exact affected versions and remediation steps.

Official advisory

• Read the official source
• CVE Record
• NVD

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