CVE-2026-70553 MaxSite CMS Unauthenticated RCE via Install Endpoint
Unauthenticated attackers can achieve persistent remote code execution by injecting PHP code into the configuration file via the install endpoint.
- Exploited in the wild
- Not known
- Login needed
- Not needed
- Attackable
- Over the internet
- Victim action needed
- Not needed
- Fix
- None listed
What is CVE-2026-70553?
CVE-2026-70553 is a critical code injection vulnerability in MaxSite CMS, published on 4 Aug 2026. An attacker can exploit it over the internet without logging in, with no action from the victim.
Official description
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.
Weakness: CWE-94
Which versions are affected by CVE-2026-70553?
How do I fix CVE-2026-70553?
No fix has been published for CVE-2026-70553 yet. Limit exposure of the affected software until one is available.
Upgrade, and never evaluate templates, expressions or code built from user input. More about Code injection.
Is CVE-2026-70553 being exploited?
There is no known exploitation of CVE-2026-70553 in the wild and no public exploit code.
Public exploit code: 1 proofs of concept on GitHub.
Sources
Also known as GHSA-32g8-v8qx-8c7w.