Cyber Resilience

CVE-2026-34216

Medium

Published: 19 May 2026

Published
19 May 2026
Modified
20 May 2026
KEV Added
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Patch
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CVSS Score v3.1 6.6 CVSS:3.1/AV:N/AC:H/PR:H/UI:N/S:U/C:H/I:H/A:H
EPSS Score 0.0041 61.5th percentile
Risk Priority 13 60% EPSS · 20% KEV · 20% CVSS

Summary

CVE-2026-34216 is a medium-severity Unsafe Reflection (CWE-470) vulnerability. Its CVSS base score is 6.6 (Medium).

Operationally, exploitation aligns with the MITRE ATT&CK technique Exploit Public-Facing Application (T1190); ranked in the top 38.5% of CVEs by exploit likelihood; it is not currently listed in the CISA KEV catalog.

EU & UK References

Vulnerability details

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…

more

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.

CWE(s)
CWE-470

Related Threats

MITRE ATT&CK Enterprise TechniquesAI

T1190 Exploit Public-Facing Application Initial Access
Adversaries may attempt to exploit a weakness in an Internet-facing host or system to initially access a network.
attack.mitre.org →
Why these techniques?

Authenticated RCE via unsafe reflection on web app admin endpoint directly enables exploitation of public-facing application.

Confidence: HIGH · MITRE ATT&CK Enterprise v18.1

Affected Assets

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In
inferred from references and description; NVD did not file a CPE for this CVE

Mitigating Controls

Likely Mitigating Controls AI

Per-CVE control mapping for this CVE has not run yet; the list below is derived from the weakness types (CWEs) cited in the NVD entry.

SC-44 Detonation Chambers
addresses: CWE-470

Externally controlled class or code selection can be resolved and invoked inside the chamber, surfacing unsafe reflection without system impact.

References