CVE-2026-46400 HAXCMS PHP has a File Upload Validation Bypass
Attackers can upload malicious PHP webshells disguised as images due to insufficient file validation, leading to remote code execution.
- Exploited in the wild
- Not known
- Login needed
- Any signed-in user
- Attackable
- Over the internet
- Victim action needed
- Not needed
- Fix
- None listed
What is CVE-2026-46400?
CVE-2026-46400 is a high-severity vulnerability in haxtheweb haxcms-php, published on 5 Jun 2026. Any signed-in user can exploit it over the network, with no action from the victim.
Official description
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.
Weakness: CWE-434
Which versions are affected by CVE-2026-46400?
How do I fix CVE-2026-46400?
No fix has been published for CVE-2026-46400 yet. Limit exposure of the affected software until one is available.
Is CVE-2026-46400 being exploited?
It is not confirmed as exploited in the wild, but public exploit code for CVE-2026-46400 exists.