RCE in Maxsite Cms
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.
Vulnerability class: RCE (Remote Code Execution)
EPSS: 0.012 (66.8th 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 105.2, 109.6
Weakness classification (CWE)
Public proof-of-concept exploits
References
- disclosure@vulncheck.com (product)
- disclosure@vulncheck.com (patch)
- disclosure@vulncheck.com (third-party-advisory)
Frequently asked questions
- What is CVE-2026-70553?
- CVE-2026-70553 is a critical-severity vulnerability in Maxsite Cms, classified under Code Injection. CVSS score: 9.8/10. Published 2026-08-04.
- How severe is CVE-2026-70553?
- Critical severity. CVSS v3 base score is 9.8 out of 10.
- Is CVE-2026-70553 known to be exploited?
- 1 public proof-of-concept repositories are indexed. Not currently listed in the CISA KEV catalog.