dbcve.org
Unrestricted File UploadWeakness · CWE-434

CVE-2026-46400

HIGH · 8.7 CVSS v4.0 Published 2026-06-05
Mitigation only
No fix yet — a mitigation exists. There is no fixed release. A documented workaround reduces exposure in the meantime.
See remediation →
93/100
Remediation priority · Urgent
Remotely reachable Zero-click

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 · unedited
HAX CMS helps manage microsite universe with PHP or NodeJs backends. Starting in version 11.0.6 and prior to version 25.0.0, the file upload functionality in HAXCMS PHP only validates file extensions using a regex pattern without checking the actual file content or MIME type. This allows attackers to upload malicious files (e.g., PHP webshells) disguised as legitimate image files, potentially leading to remote code execution. Version 25.0.0 contains a fix for the issue.

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 confidence

HAX CMS PHP versions 11.0.6 through 24.x contain a file upload vulnerability where only file extensions are validated via regex pattern, without checking actual file content or MIME type. This allows attackers to upload malicious PHP webshells disguised as legitimate image files, leading to potential remote code execution.

MitigationUpgrade to version 25.0.0 which contains the fix, or implement proper file content validation and MIME type checking in the upload handler to ensure uploaded files match their claimed type.

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
Authentication
X
User interaction
None
Scope
X

CVSS:4.0/AV:N/AC:L/AT:N/PR:L/UI:N/VC:H/VI:H/VA:H/SC:N/SI:N/SA:N/E:X/CR:X/IR:X/AR:X/MAV:X/MAC:X/MAT:X/MPR:X/MUI:X/MVC:X/MVI:X/MVA:X/MSC:X/MSI:X/MSA:X/S:X/AU:X/R:X/V:X/RE:X/U:X

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 checks

Work through these to decide whether this CVE applies to you.

  1. Identify HAX CMS installation and version
    Locate the HAX CMS installation directory and check the version indicator (such as version file, package.json, or composer.json)
    Affected if The installed version is below 25.0.0 (or version cannot be determined)
  2. Verify file upload functionality is enabled
    Check if the PHP backend file upload module or endpoint is active and accessible in the application
    Affected if File upload functionality is enabled and accessible to users
  3. Inspect upload directory for script execution rights
    Examine the web server configuration for the designated upload directory - verify whether PHP or other executable scripts can be run from this location
    Affected if The upload directory allows execution of PHP files or other scripts
  4. Review file upload validation logic
    Examine the backend PHP code that handles file uploads - look for the regex pattern used for extension validation and determine if MIME type or file content validation is performed
    Affected if Only extension-based regex validation exists without MIME type or file content checks

A user is affected if running HAX CMS PHP backend version below 25.0.0 with file upload enabled, an upload directory that permits script execution, and extension-only validation logic.

Generated from the published advisory. Verify against your own configuration.

Check your environment

Paste your version and any relevant configuration and it will be compared against the affected criteria above. Do not include secrets or credentials.

AI-assisted, checked against the advisory. Informational, not a guarantee.

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 · scoped
Mitigation available No clean upgrade yet — mitigate in the meantime
Mitigation

Upgrade to version 25.0.0 which contains the fix, or implement proper file content validation and MIME type checking in the upload handler to ensure uploaded files match their claimed type.

Recommended fix High confidence

HAXCMS version 25.0.0

  1. 1. Backup the existing HAXCMS installation, including all files and the database
  2. 2. Review the HAXCMS version 25.0.0 release notes and upgrade documentation for any migration requirements
  3. 3. Test the upgrade in a non-production/staging environment first to verify compatibility
  4. 4. Upgrade the HAXCMS PHP installation to version 25.0.0
  5. 5. Verify that the file upload functionality now properly validates file content and MIME types beyond just extension checking
  6. 6. Confirm the remote code execution vulnerability is mitigated by testing that malicious files (e.g., PHP files with image extensions) are rejected
Caveat Upgrading from version 11.x-24.x to version 25.0.0 is a significant version jump; review release notes for potential breaking changes in API, themes, or configuration

Generated from the published advisory — verify against the referenced sources before acting.

Have this fixed Scoped from the published advisory
  • Consultation4.0 h
  • Implementation8.0 h
  • Testing4.0 h
  • Review / QA3.0 h
19.0 hours of engineering $3,380
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References Go to the primary sourcePrimary sources — vendor advisories, patches and trackers. Where our summary and a reference disagree, the reference wins.

Primary sources

Practitioner notes

Contributed

Peer-ranked notes from engineers who’ve handled CVE-2026-46400 in production — separate from our analysis above.

No notes yet

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What this is

A place for practitioners to share what actually worked: a mitigation you’ve tested, a configuration change, a version- or environment-specific caveat, or a link to a verified patch. The most useful notes rise to the top as peers upvote them, so the signal stays high.

What belongs here
  • 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