CVE-2026-70553
MaxSite CMS Unauthenticated RCE via Install Endpoint
CRITICAL 9.3EPSS 1.3%
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.
- Affected
- MaxSite · MaxSite CMS
- CVSS v4.0 VULNCHECK
- 9.3 CRITICAL
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/E:X/CR:X/IR:X/AR:X/MAV:X/MAC:X/MAT:X/MPR:X/MUI:X/MVC:X/MVI:X/MVA:X/MSC:X/MSI:X/MSA:X/S:X/AU:X/R:X/V:X/RE:X/U:X - CVSS v3.1 VULNCHECK
- 9.8 CRITICAL
CVSS:3.1/AV:N/AC:L/PR:N/UI:N/S:U/C:H/I:H/A:H - EPSS
- 1.27% chance of exploitation in the next 30 days, 69th percentile
- Published
- 2026-08-04
- Updated
- 2026-08-14
Proof-of-concept exploits (1)
- woshidashabi1126/CVE-2026-70553-PoC1★ · 2026-08-06