XSS in Open-Webui
CVE-2026-45318
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.
Vulnerability class: XSS (Cross-Site Scripting)
Published · last modified .
CVSS v3 metric
CVSS v3 base score 5.4 (Medium). Vector: CVSS:3.1/AV:N/AC:L/PR:L/UI:R/S:C/C:L/I:L/A:N.
EPSS exploit prediction
EPSS: 0.002 (13.4th percentile), scored .
Very low probability of exploitation in the next 30 days; routine patching cadence is appropriate. 13th percentile — 13.4% of CVEs in the catalogue have a lower EPSS than this one. How to read EPSS.
EPSS over last 30 days · oldest: 0.002 · newest: 0.002 · change: +0.000
Affected products
- Open-Webui — versions < 0.9.3
- Openwebui Open Webui
Weakness classification (CWE)
References
- github.com/open-webui/open-webui/security/advisories/GHSA-hcwp-82g6-8wxc (Exploit, Mitigation, Vendor Advisory)
Frequently asked questions
- What is CVE-2026-45318?
- CVE-2026-45318 is a medium-severity vulnerability in Open-Webui, classified under Cross-site Scripting. CVSS score: 5.4/10. Published 2026-05-15.
- How severe is CVE-2026-45318?
- Medium severity. CVSS v3 base score is 5.4 out of 10.