Vulnerability · Published Sep 9, 2026 · Assigned by VulnCheck

CVE-2026-87928MaxSite CMS 0.94 through 109.6 HTML Upload XSS via admin_page

Medium 5.4

In plain English

A medium-severity unrestricted file upload in MaxSite CMS from MaxSite. There are no confirmed reports of exploitation so far. The chance it is exploited in the next 30 days is estimated at 0.3% (higher than 23% of all known vulnerabilities).

Severity (CVSS 3.1)5.4Medium

Exploit odds (30 days)0.3%top 77.4% of all CVEs

Exploited in the wildNo reportsCISA SSVC: none

Attack toolingNoneno public tooling known

Official description

MaxSite CMS versions 0.94 through 109.6 contain a cross-site scripting vulnerability in the admin_page upload handler that allows any logged-in user to upload HTML files. Attackers can upload HTML containing malicious scripts to the uploads/_pages/ directory, which executes in visitors' browsers when the file is accessed, enabling persistent stored cross-site scripting attacks.

Affected products (as reported)

Vendor	Product	Versions
MaxSite	MaxSite CMS	0.94 – through 109.6

Weakness: CWE-434 · Vector: CVSS:3.1/AV:N/AC:L/PR:L/UI:R/S:C/C:L/I:L/A:N

References

https://github.com/maxsite/cms product
https://github.com/EviL0rd/maxsite-cve2/blob/main/2026.09.08-maxsite-cms-arbitrary-file-write-stored-xss.md exploit, technical-description
https://github.com/maxsite/cms/blob/2ca0a0c7d1d71106a25dbb0f2aedaaefbf12802c/application/maxsite/admin/plugins/admin_page/uploads-require-maxsite.php#L1-L64 technical-description
VulnCheck Advisory: MaxSite CMS 0.94 through 109.6 HTML Upload XSS via admin_page third-party-advisory