CVE-2026-63418

Name of the Vulnerable Software and Affected Versions Monitoring Plugins versions 3.0.0-rc1 through 3.0.0

Description The check icmp plugin stores the number of hosts provided via the -H or --Host command-line arguments, or through --extra-opts files containing Host= entries, using an unsigned short. Providing more than 65,535 hosts causes an integer wrap, leading the process arguments() function to allocate an undersized hosts array. This results in an out-of-bounds write to heap memory before the main() function calls setuid(getuid()). On systems where check icmp is configured as setuid root, a local low-privileged attacker can corrupt heap memory while the process maintains root privileges.

Recommendations Update to version 3.0.1. As a temporary mitigation, avoid using the -H or --Host parameters with more than 65,535 entries.