HAXCMS PHP has a File Upload Validation Bypass
CVE-2026-46400

8.7HIGH

Key Information:

Vendor

Haxtheweb

Status
Haxcms-PHP
Vendor
CVE Published:
5 June 2026

What is CVE-2026-46400?

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.

Affected Version(s)

haxcms-php >= 11.0.6, < 25.0.0

References

https://github.com/haxtheweb/issues/security/advisories/G...
x_refsource_CONFIRM

CVSS V4

Score:
8.7
Severity:
HIGH
Confidentiality:
High
Integrity:
High
Availability:
High
Attack Vector:
Network
Attack Complexity:
Low
Attack Required:
None
Privileges Required:
Undefined
User Interaction:
None

Timeline

  • Vulnerability published

  • Vulnerability Reserved

.