Medium severity · published Sep 9, 2026
CVE-2026-87928
MaxSite CMS 0.94 through 109.6 HTML Upload XSS via admin_page
5.4
CVSS
0.3%
EPSS
No
On KEV
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.
CVSS vector
CVSS:3.1/AV:N/AC:L/PR:L/UI:R/S:C/C:L/I:L/A:N
Attack vector
Network
Complexity
Low
Privileges
Low
User interaction
Required
Confidentiality
Low
Integrity
Low
Availability
None
Scope
Changed
Exploitation
Is it being used?
Exploit prediction (EPSS)0.3% · higher than 22% of CVEs
Exploited in the wildNo evidence yet
CISA KEVNot listed
Ransomware campaign useNot known
Affected products
Which versions
MC
MaxSite CMS · MaxSite
0.94 through 109.6 · source: vendor
References
NVD
https://nvd.nist.gov/vuln/detail/CVE-2026-87928
CVE.org
https://www.cve.org/CVERecord?id=CVE-2026-87928
github.com
https://github.com/EviL0rd/maxsite-cve2/blob/main/2026.09.08-maxsite-cms-arbitrary-file-write-stored-xss.md
github.com
https://github.com/maxsite/cms
github.com
https://github.com/maxsite/cms/blob/2ca0a0c7d1d71106a25dbb0f2aedaaefbf12802c/application/maxsite/admin/plugins/admin_page/uploads-require-maxsite.php#L1-L64
www.vulncheck.com
https://www.vulncheck.com/advisories/maxsite-cms-0.94-through-109.6-html-upload-xss-via-admin-page
More from MaxSite CMS
9.8
CVE-2026-87929
MaxSite CMS through 109.6 Authentication Bypass via Hardcoded Encryption Key
9.8
CVE-2026-70554
MaxSite CMS Unauthenticated PHP Object Injection via maxsite_comuser Cookie
9.8
CVE-2026-70553
MaxSite CMS Unauthenticated RCE via Install Endpoint
9.8
CVE-2026-70552
MaxSite CMS 109.5 Unauthenticated AJAX Dispatcher Bypass via ajax.php
8.2
CVE-2026-87927
MaxSite CMS through 109.6 Local File Inclusion via ajax dispatcher