CVE-2026-45318 Details
Description
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.
A stored cross-site scripting (XSS) vulnerability has been identified in Open WebUI versions prior to 0.9.3. This issue arises from the improper handling of user-uploaded Office files (Excel and DOCX) in the file preview feature. The application renders these files as HTML using Svelte's ' {@html} ' directive without proper sanitization, creating an opportunity for XSS attacks. The vulnerability was reintroduced after version 0.8.0 and affects several different versions and ranges up to and including 0.9.2.
To address this vulnerability, apply DOMPurify sanitization to all three file preview paths in the Svelte components. Alternatively, create a wrapper component that automatically applies DOMPurify, ensuring consistent sanitization across the application.
Metrics
CVSS 4.0 Severity and Vector Strings:
No CVSS 4.0 data is available for this CVE.
CVSS 3.x Severity and Vector Strings:
No data available for CVSS Version 2.0 on this CVE.
CISA-ADP
Assessed May 18, 2026References to Advisories, Solutions, and Tools
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| URL | Source(s) | Tag(s) |
|---|---|---|
| https://github.com/open-webui/open-webui/security/advisories/GHSA-hcwp-82g6-8wxc | CISA-ADP | ExploitMitigationVendor Advisory |
| https://github.com/open-webui/open-webui/security/advisories/GHSA-hcwp-82g6-8wxc | [email protected] | ExploitMitigationVendor Advisory |
Weakness Enumeration
| CWE-ID | CWE Name | Source |
|---|---|---|
| CWE-79 | Improper Neutralization of Input During Web Page Generation ('Cross-site Scripting') | [email protected] |
Affected Products
| Product | Versions |
|---|---|
| openwebui open webui | < 0.9.3 |
CPE
Remediation
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Change History
5 change records found show changes
| Date | Action | Recorded By |
|---|---|---|
| Jun 17, 2026 | CVE Modified | [email protected] |
| Jun 17, 2026 | CVE Modified | CISA-ADP |
| May 18, 2026 | Initial Analysis | [email protected] |
| May 18, 2026 | CVE Modified | CISA-ADP |
| May 15, 2026 | New CVE Received | [email protected] |