CVE-2026-70553: critical vulnerability in MaxSite CMS
MaxSite CMS Unauthenticated RCE via Install Endpoint
Published · Updated
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48Vexday Risk Score
No sign of exploitation. It has a public proof of concept.
ssvc Attendcvss 9.3epss 1.3%
from disclosure to weapon2 days
Published on NVDAug 4
1st PoC+2d
MaxSite CMS contains a remote code execution vulnerability that allows unauthenticated attackers to inject arbitrary PHP code into the application configuration file by submitting crafted POST requests to the install endpoint after installation is complete. Attackers can supply a malicious db_dbprefix value containing a single quote to break out of a PHP string literal in application/config/database.php, appending attacker-controlled PHP statements that are executed by the web server on every subsequent request, resulting in persistent unauthenticated remote code execution as the web-server process user.
CVSS:4.0/AV:N/AC:L/AT:N/PR:N/UI:N/VC:H/VI:H/VA:H/SC:N/SI:N/SA:N
Affected products
MaxSite · MaxSite CMSpublic PoCs found — 1
githubgithub.com/woshidashabi1126/CVE-2026-70553-PoC★ 1⚠ Public resources, to assess the exposure of systems you control or are authorized to test. Test only with authorization.
Related CVEs — MaxSite CMS
In the same product, most dangerous first.
CVE-2026-70554CRITICALMaxSite CMS Unauthenticated PHP Object Injection via maxsite_comuser CookieEPSS 1.2%CVE-2026-70552CRITICALMaxSite CMS 109.5 Unauthenticated AJAX Dispatcher Bypass via ajax.phpEPSS 0.8%CVE-2026-87930CRITICALMaxSite CMS through 109.6 PHP Object Injection via ci_sessionEPSS 0.6%CVE-2026-87927HIGHMaxSite CMS through 109.6 Local File Inclusion via ajax dispatcherEPSS 0.6%CVE-2026-87929CRITICALMaxSite CMS through 109.6 Authentication Bypass via Hardcoded Encryption KeyEPSS 0.5%CVE-2026-87928MEDIUMMaxSite CMS 0.94 through 109.6 HTML Upload XSS via admin_pageEPSS 0.3%