CVE-2026-46392: HAX CMS PHP Has a Stored XSS via Case-Sensitivity Mismatch in HTML Upload Validation
haxtheweb · haxcms-php
Affected: haxtheweb haxcms-php · Exploitation: unlikely (under 1%)
Not in CyberSIXT coverage yet: no article names this CVE. This page shows the public record.
Higher than 19% of scored CVEs
DescriptionCVE.org
HAX CMS helps manage microsite universe with PHP or NodeJs backends. Prior to version 26.0.0 of HAX CMS PHP, the `saveFile` endpoint validates upload extensions case-insensitively and writes the filename to disk verbatim, but the `.htaccess` rule that forces `Content-Disposition: attachment` on HTML files is case-sensitive. An HTML file uploaded with an uppercase extension (`.HTML`, `.Html`, `.HTM`) is still served as `text/html` but the forced-download header never applies, so the browser renders it inline and executes any embedded JavaScript in the HAXcms origin. This bypasses the mitigation shipped for CVE-2026-22704. Version 26.0.0 contains a fix.
Affected products1
From the CVE record. A product or version that is not listed is unknown, not unaffected.
- haxtheweb · haxcms-php< 26.0.0
On the Atlas
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CoverageNo articles yet
No CyberSIXT article names CVE-2026-46392 yet, so there is no coverage timeline, action brief or change log for it. Everything on this page comes from the public CVE record, CISA KEV, EPSS and the nuclei template index. Search the archive or see the CVEs in the news.