CVE-2026-34234

CRITICAL
Published May 19, 2026 Modified May 20, 2026 CWE-78 CWE-284

Description

CtrlPanel is open-source billing software for hosting providers. In versions 1.1.1 and prior, the web-based installer (public/installer/index.php) is vulnerable to unauthenticated Remote Code Execution (RCE) because it performs the install.lock check only after including and executing form handler files, leaving installer endpoints reachable on already-installed instances. The handlers also pass unsanitized user input directly into shell commands, allowing an attacker to submit crafted requests that execute arbitrary commands on the server. The vulnerability stems from two combined weaknesses: (1) premature form handler execution before the lock file gate, and (2) unsafe use of user input in shell command construction. This issue is reported to be actively exploited in the wild. The issue has been fixed in version 1.2.0.

CVSS v3.1 Score

10.0
CRITICAL
CVSS:3.1/AV:N/AC:L/PR:N/UI:N/S:C/C:H/I:H/A:H

EPSS — Exploit Prediction

0.0009
Probability of exploitation
0.25%
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-78 OS Command Injection
CWE-284 CWE-284

References

Frequently Asked Questions

What is CVE-2026-34234? +
CtrlPanel is open-source billing software for hosting providers. In versions 1.1.1 and prior, the web-based installer (public/installer/index.php) is vulnerable to unauthenticated Remote Code Execution (RCE) because it performs the install.lock check only after including and executing form handler files, leaving installer endpoints reachable on already-installed instances. The handlers also pass unsanitized user input directly into shell commands, allowing an attacker to submit crafted requests that execute arbitrary commands on the server. The vulnerability stems from two combined weaknesses: (1) premature form handler execution before the lock file gate, and (2) unsafe use of user input in shell command construction. This issue is reported to be actively exploited in the wild. The issue has been fixed in version 1.2.0. It has a CVSS v3.1 base score of 10.0 (CRITICAL).
How severe is CVE-2026-34234? +
CVE-2026-34234 has a CVSS v3.1 score of 10.0 out of 10, rated CRITICAL. This is a critical vulnerability that should be patched immediately. The EPSS score is 0.0009, placing it in the 0th percentile for exploitation probability.
How do I check if I'm vulnerable to CVE-2026-34234? +
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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