Vulnerability · Published Jun 5, 2026 · Assigned by GitHub_M

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

High 8.7

In plain English

A high-severity unrestricted file upload in haxcms-php from haxtheweb. Proof-of-concept exploit code is public. The chance it is exploited in the next 30 days is estimated at 0.4% (higher than 33% of all known vulnerabilities).

Severity (CVSS 4.0)8.7High

Exploit odds (30 days)0.4%top 67.1% of all CVEs

Exploited in the wildNo reportsCISA SSVC: poc

Attack toolingNoneno public tooling known

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.

Affected products (as reported)

Vendor	Product	Versions
haxtheweb	haxcms-php	>= 11.0.6, < 25.0.0

Weakness: CWE-434 · Vector: 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

References

https://github.com/haxtheweb/issues/security/advisories/GHSA-ffxv-9qv2-v2v8 x_refsource_CONFIRM