CVE-2026-46392
Official description Straight from the sourceThe vendor's or NVD's own wording, published unedited. Authoritative, but often terse — it says what broke, rarely what to do.
NVD · uneditedHAX 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.
Technical summary Written by usOur analysis, written from the advisory, the CVSS vector and the affected-version data. It adds context the advisory leaves out, and never invents facts that are not in the source.
dbcve analysis · high confidenceThe saveFile endpoint in HAX CMS PHP validates file extensions case-insensitively but writes filenames to disk verbatim, while the .htaccess rule forcing Content-Disposition: attachment on HTML files is case-sensitive. Uploading files with uppercase extensions like .HTML, .HTM, or .Html bypasses the forced-download header, allowing browsers to render the HTML inline and execute embedded JavaScript in the HAXcms origin, bypassing the prior CVE-2026-22704 mitigation.
Verify against the referenced sources before acting — the references below are authoritative for this CVE, this summary is not.
CVSS breakdown How the score is builtThe industry scoring standard. It rates how the flaw is reached, what it takes to exploit, and what an attacker gains — the score is derived from those, not the other way round.
From the vector- Attack vector
- Network
- Complexity
- Low
- Privileges
- Low
- User interaction
- Required
- Scope
- Changed
- Confidentiality
- High
- Integrity
- High
- Availability
- None
CVSS:3.1/AV:N/AC:L/PR:L/UI:R/S:C/C:H/I:H/A:N
Am I affected? How to checkSteps we derive from the advisory and the affected-version data, so you can decide whether this CVE reaches your setup. They are a guide, not a scan — your own configuration is the authority.
dbcve checksWork through these to decide whether this CVE applies to you.
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Identify if HAX CMS PHP is installedLook for HAX CMS PHP installation directories or files, typically in web root. Common paths include /haxcms, /cms, or check for haxcms-related PHP files and directories.Affected if HAX CMS PHP is present in the environment and the saveFile endpoint is accessible.
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Check HAX CMS PHP versionLocate the version file or header in the HAX CMS installation (often in a version.php, package.json, or similar file at the root of the HAXcms directory). Compare the installed version to the fixed version 26.0.0.Affected if The installed version is earlier than 26.0.0.
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Verify if saveFile endpoint is accessibleCheck for the presence of the saveFile PHP endpoint in the HAX CMS installation, typically at /api/saveFile or similar endpoint path under the HAXcms directory.Affected if The saveFile endpoint exists and is reachable via HTTP/HTTPS.
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Inspect uploaded files for uppercase extensionsSearch upload directories within the HAX CMS installation for files with uppercase HTML extensions such as .HTML, .HTM, .Html, .HTM, or other case variants. Common upload paths include /files, /uploads, or media directories.Affected if Any files with uppercase .HTML or .HTM extensions exist in the system upload directories.
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Check .htaccess for case-sensitive extension rulesLocate and examine the .htaccess file in the HAX CMS web directory. Look for RewriteCond rules that match file extensions for Content-Disposition: attachment headers, and verify if they handle case variations (check for [NC] flag which indicates case-insensitive matching).Affected if The .htaccess rules do NOT include the [NC] flag for HTML extension matching, making them case-sensitive and vulnerable to bypass.
A user is affected if HAX CMS PHP version is below 26.0.0, the saveFile endpoint is accessible, and uppercase HTML file extensions can bypass the .htaccess forced-download rules.
Generated from the published advisory. Verify against your own configuration.
Remediation Closing itWhat it takes to close this. Where a vendor fix exists we point at it; where none exists we say so plainly, and can build one. Effort estimates are scoped from the advisory, not from your codebase.
dbcve · scopedUpgrade HAX CMS PHP to version 26.0.0 or later, which contains the fix for case-sensitive extension handling.
HAX CMS PHP version 26.0.0 or later
- 1. Identify the current version of HAX CMS PHP installation by checking the version file or admin panel.
- 2. Create a complete backup of the HAX CMS installation including all files, database, and configuration.
- 3. Download HAX CMS PHP version 26.0.0 or later from the official repository (github.com) or your package manager.
- 4. Replace the existing HAX CMS files with the new version, preserving configuration files and custom content.
- 5. Verify the upgrade was successful by checking the version number in the admin interface.
- 6. Test that HTML files with uppercase extensions (.HTML, .Html, .HTM) are now properly handled and receive the Content-Disposition: attachment header.
Generated from the published advisory — verify against the referenced sources before acting.
- Consultation1.0 h
- Implementation2.0 h
- Testing1.0 h
- Review / QA1.0 h
An estimate, not a bill — we confirm scope with you before any work starts. Need it this week? Rush from $1,424.
Scan for this in your stack
Free · runs locallyCheck whether your project pulls in CVE-2026-46392 — or any other known-vulnerable package — straight from your lock files. Free and open source; it runs locally and uploads nothing.
References Go to the primary sourcePrimary sources — vendor advisories, patches and trackers. Where our summary and a reference disagree, the reference wins.
Primary sourcesPractitioner notes
ContributedPeer-ranked notes from engineers who’ve handled CVE-2026-46392 in production — separate from our analysis above.
The advisory tells you what broke. It rarely tells you what actually worked. If you’ve dealt with this one, that detail is what the next engineer is searching for.
- The version that genuinely resolved it — not the one the vendor claimed
- A config change or rule that shut the vector down
- A gotcha in the upgrade path that cost you an afternoon
No notes yet
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- Verified mitigations, workarounds, and config changes
- Version or environment caveats, and links to real fixes
- No weaponised exploit code, or anything meant to cause harm
- No spam, self-promotion, credentials, or personal data