CVE-2026-34216

MEDIUM
Published May 19, 2026 Modified May 20, 2026 CWE-470

Description

CtrlPanel is open-source billing software for hosting providers. In versions 1.1.1 and prior, the admin settings update endpoint accepted a fully qualified class name directly from user-supplied request input and used it for dynamic static method calls and object instantiation without any allowlist validation, allowing for authenticated Remote Code Execution. An authenticated admin-level user could supply an arbitrary class name available in the Composer autoloader, potentially triggering unintended constructor or magic method execution. The update() method reads settings_class directly from the HTTP request and passed it to new $settings_class() and $settings_class::getValidations() without verifying that the provided value corresponds to a legitimate settings class: Because PHP resolves class names against the Composer autoloader at runtime, any autoloadable class in the application or its dependencies could be instantiated. Depending on the classes available in the dependency tree, this can trigger unintended side effects through constructors or magic methods (__construct, __toString, __wakeup), following a PHP object injection / gadget chain pattern. This issue has been fixed in version 1.2.0.

CVSS v3.1 Score

6.6
MEDIUM
CVSS:3.1/AV:N/AC:H/PR:H/UI:N/S:U/C:H/I:H/A:H

EPSS — Exploit Prediction

0.0041
Probability of exploitation
0.61%
Percentile rank

EPSS estimates the probability that this vulnerability will be exploited in the wild within the next 30 days. A higher score means more likely to be exploited.

Weakness Type (CWE)

CWE-470 CWE-470

References

Frequently Asked Questions

What is CVE-2026-34216? +
CtrlPanel is open-source billing software for hosting providers. In versions 1.1.1 and prior, the admin settings update endpoint accepted a fully qualified class name directly from user-supplied request input and used it for dynamic static method calls and object instantiation without any allowlist validation, allowing for authenticated Remote Code Execution. An authenticated admin-level user could supply an arbitrary class name available in the Composer autoloader, potentially triggering unintended constructor or magic method execution. The update() method reads settings_class directly from the HTTP request and passed it to new $settings_class() and $settings_class::getValidations() without verifying that the provided value corresponds to a legitimate settings class: Because PHP resolves class names against the Composer autoloader at runtime, any autoloadable class in the application or its dependencies could be instantiated. Depending on the classes available in the dependency tree, this can trigger unintended side effects through constructors or magic methods (__construct, __toString, __wakeup), following a PHP object injection / gadget chain pattern. This issue has been fixed in version 1.2.0. It has a CVSS v3.1 base score of 6.6 (MEDIUM).
How severe is CVE-2026-34216? +
CVE-2026-34216 has a CVSS v3.1 score of 6.6 out of 10, rated MEDIUM. This is a medium-severity vulnerability that should be remediated as part of regular maintenance. The EPSS score is 0.0041, placing it in the 1th percentile for exploitation probability.
How do I check if I'm vulnerable to CVE-2026-34216? +
You can use Secably's free Website Scanner to check your website for known vulnerabilities. For infrastructure scanning, use the Port Scanner to identify exposed services that may be affected. Check the vendor advisories linked above for specific patch and version information.

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