Auth bypass in Maxsite Cms
CVE-2026-70552
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.
Vulnerability class: Broken Authentication
EPSS: 0.006 (45.7th percentile) — read the EPSS interpretation.
CVSS v3 metric
CVSS v3 base score 9.8 (Critical). Vector: CVSS:3.1/AV:N/AC:L/PR:N/UI:N/S:U/C:H/I:H/A:H.
Affected products
- Maxsite Cms — versions 0.78, 109.6
Weakness classification (CWE)
References
- disclosure@vulncheck.com (product)
- disclosure@vulncheck.com (patch)
- disclosure@vulncheck.com (third-party-advisory)
Frequently asked questions
- What is CVE-2026-70552?
- CVE-2026-70552 is a critical-severity vulnerability in Maxsite Cms, classified under Missing Authentication for Critical Function. CVSS score: 9.8/10. Published 2026-08-04.
- How severe is CVE-2026-70552?
- Critical severity. CVSS v3 base score is 9.8 out of 10.