{"id":"CVE-2026-46392","aliases":["EUVD-2026-34883"],"status":"published","title":"HAX CMS PHP Has a Stored XSS via Case-Sensitivity Mismatch in HTML Upload Validation","description":"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.","severity":{"version":"3.1","score":8.7,"vector":"CVSS:3.1/AV:N/AC:L/PR:L/UI:R/S:C/C:H/I:H/A:N","level":"high","assessor":"cna","from":"cve"},"epss":{"day":"2026-11-10","score":0.00272,"percentile":0.19717,"model":"v2026.06.15"},"facts":{"in_kev":false,"known_exploited":false,"public_exploit":false,"fix_available":false},"cwes":["CWE-178","CWE-434"],"published":"2026-06-05T18:20:25Z","modified":"2026-10-26T11:10:00Z","products":[{"vendor":"haxtheweb","product":"haxcms-php"}],"references":[{"url":"https://github.com/haxtheweb/issues/security/advisories/GHSA-hg33-w4j2-95qp","tags":["x_refsource_CONFIRM","exploit"]}],"sources":{"cve":[{"id":"CVE-2026-46392","title":"HAX CMS PHP Has a Stored XSS via Case-Sensitivity Mismatch in HTML Upload Validation","description":"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.","status":"published","published":"2026-06-05T18:20:25.658Z","modified":"2026-06-05T19:11:31.488Z","cvss":[{"version":"3.1","score":8.7,"vector":"CVSS:3.1/AV:N/AC:L/PR:L/UI:R/S:C/C:H/I:H/A:N","level":"high","assessor":"cna"}],"cwes":["CWE-178","CWE-434"],"updated_at":"2026-11-02T13:47:06.353366Z"}],"euvd":[{"id":"EUVD-2026-34883","description":"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.","status":"published","published":"2026-06-05T18:20:25Z","modified":"2026-06-05T19:11:31Z","cvss":[{"version":"3.1","score":8.7,"vector":"CVSS:3.1/AV:N/AC:L/PR:L/UI:R/S:C/C:H/I:H/A:N","level":"high"}],"updated_at":"2026-11-02T18:20:50.934862Z"}],"nvd":[{"id":"CVE-2026-46392","description":"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.","status":"published","published":"2026-06-05T19:16:33.16Z","modified":"2026-10-26T11:10:00.157Z","cvss":[{"version":"3.1","score":8.7,"vector":"CVSS:3.1/AV:N/AC:L/PR:L/UI:R/S:C/C:H/I:H/A:N","level":"high","assessor":"secondary"}],"cwes":["CWE-178","CWE-434"],"updated_at":"2026-11-02T14:12:22.73178Z"}]}}