Critical severity · published Aug 4, 2026
CVE-2026-70552
MaxSite CMS 109.5 Unauthenticated AJAX Dispatcher Bypass via ajax.php
9.8
CVSS
0.8%
EPSS
No
On KEV
Description
MaxSite CMS 109.5 and earlier contains an authentication bypass vulnerability in the AJAX dispatcher that allows unauthenticated attackers to access admin-gated endpoints by supplying any X-Requested-With header and requesting a base64-encoded path resolving to any *-ajax.php file in the codebase. Attackers can exploit this dispatcher bypass to reach privileged plugin endpoints without credentials, enabling actions such as manipulating poll states and vote counts, and amplifying the impact of any dangerous operation performed by admin-only ajax files across the plugin tree.
CVSS vector
CVSS:3.1/AV:N/AC:L/PR:N/UI:N/S:U/C:H/I:H/A:H
Attack vector
Network
Complexity
Low
Privileges
None
User interaction
None
Confidentiality
High
Integrity
High
Availability
High
Scope
Unchanged
Exploitation
Is it being used?
Exploit prediction (EPSS)0.8% · higher than 57% of CVEs
Exploited in the wildNo evidence yet
CISA KEVNot listed
Ransomware campaign useNot known
Affected products
Which versions
MC
MaxSite CMS · MaxSite
0.78 through 109.5 · source: vendor
Affected product
MC
MaxSite CMS
MaxSite
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