Vulnerability Report

CVE-2026-70553

RCE

Title: Unauthenticated RCE in MaxSite CMS install endpoint

RCE

Proof Of Concept

PoC Available for CVE-2026-70553

CWE Category CWE-94
Published Date Aug 04, 2026
Modified Date Aug 05, 2026
Exploit Status Available
Score 9.3 CVSS v4.0
Exploit Probability (EPSS)
0.88%

Vulnerability Summary

CVE-2026-70553: 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.

Impacted Vendors

Analysis in Progress...

Reference Links

https://github.com/maxsite/cms https://max-3000.com/page/maxsite-cms-109-6 https://www.vulncheck.com/advisories/maxsite-cms-unauthenticated-rce-via-install-endpoint
CVSS v4.0
Source Entity [email protected]
Severity CRITICAL
9.3
Attack Vector
NETWORK
Complexity
LOW
Privileges
N/A
Interaction
NONE
Confidentiality
N/A
Integrity
N/A
Availability
N/A
Scope
N/A
RAW VECTOR 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
Source Entity [email protected]
Severity CRITICAL
9.8
Attack Vector
NETWORK
Complexity
LOW
Privileges
N/A
Interaction
NONE
Confidentiality
N/A
Integrity
N/A
Availability
N/A
Scope
UNCHANGED
RAW VECTOR CVSS:3.1/AV:N/AC:L/PR:N/UI:N/S:U/C:H/I:H/A:H

Associated Attack Patterns (CAPEC)

Total: Patterns

CVE-2026-70553 Exploits & PoCs (Proof Of Concept)

GitHub https://github.com/woshidashabi1126/CVE-2026-70553-PoC
View Code
MODIFIED

Vulnerability data updated via NVD.

MODIFIED

Vulnerability data updated via NVD.

Attack Vector Matrix

Access Vector NETWORK
Complexity LOW
Privileges N/A
Interaction NONE
CVSS Vector String 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

Affected Stack

No specific products linked.