CVE-2026-26279
Published: 03 March 2026
Description
Froxlor is open source server administration software. Prior to 2.3.4, a typo in Froxlor's input validation code (== instead of =) completely disables email format checking for all settings fields declared as email type. This allows an authenticated admin to…
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store arbitrary strings in the panel.adminmail setting. This value is later concatenated into a shell command executed as root by a cron job, where the pipe character | is explicitly whitelisted. The result is full root-level Remote Code Execution. This vulnerability is fixed in 2.3.4.
Mitigating Controls (NIST 800-53 r5)AI
Directly enforces validation of email-type inputs like panel.adminmail to prevent storage of arbitrary strings containing command injection payloads such as the whitelisted pipe character.
Requires timely remediation of the specific software flaw—a validation typo using == instead of =—through patching to Froxlor version 2.3.4.
Limits the server administration software to least functionality by prohibiting or restricting root cron jobs that concatenate untrusted configuration data into shell commands.
Security SummaryAI
CVE-2026-26279 is a critical vulnerability in Froxlor, an open source server administration software. Prior to version 2.3.4, a typo in the input validation code—using == instead of =—completely disables email format checking for all settings fields declared as email type. This flaw allows arbitrary strings to be stored in the panel.adminmail setting, which is later concatenated into a shell command executed as root by a cron job. The pipe character | is explicitly whitelisted in this command, enabling command injection. The vulnerability is associated with CWE-78 (Improper Neutralization of Special Elements used in an OS Command) and CWE-482 (Comparing instead of Assigning), and carries a CVSS v3.1 base score of 9.1 (AV:N/AC:L/PR:H/UI:N/S:C/C:H/I:H/A:H).
An authenticated administrator can exploit this vulnerability remotely with low complexity. By supplying a malicious string containing a whitelisted pipe character to the panel.adminmail field, the attacker injects arbitrary commands into the root-executed cron job shell command. Successful exploitation results in full root-level remote code execution on the server.
The Froxlor security advisory (GHSA-33mp-8p67-xj7c) details the issue and confirms it is fixed in version 2.3.4. The patching commit (22249677107f8f39f8d4a238605641e87dab4343) corrects the validation typo, and administrators are directed to upgrade to the 2.3.4 release for mitigation.
Details
- CWE(s)
Affected Products
MITRE ATT&CK Enterprise TechniquesAI
Why these techniques?
The vulnerability enables exploitation for privilege escalation (T1068) from authenticated admin to root RCE via command injection (T1059.004 Unix Shell) in a root cron job on a remote service (T1210).