CVE-2026-56117

Name of the Vulnerable Software and Affected Versions dhcpcd versions prior to 10.3.2

Description A heap use-after-free issue exists in the control socket handling within src/control.c. This occurs when privilege separation is disabled or initialization fails, leaving the control socket in mode 0666. A local unprivileged attacker can trigger memory corruption by connecting to the control socket and sending a privileged command, such as -x. This sequence causes the control recvdata() function to free the client object, while a subsequent READ+HANGUP event passes a stale pointer to the control hangup() function.

Recommendations Update dhcpcd to the version containing commit 78ea09e. Enable privilege separation to prevent unprivileged users from accessing the control socket. Restrict the permissions of the control socket to avoid mode 0666.