CVE-2026-56117
MediumCVSS 4.7Exploitation Probability (EPSS)
Low risk1th percentile — higher than 1% of all known CVEs
Summary
A heap use-after-free vulnerability in dhcpcd through version 10.3.2, fixed in commit 78ea09e, exists in the control socket handling within src/control.c. Local unprivileged attackers can trigger memory corruption when privilege separation is disabled by sending a privileged command (e.g., -x) via the control socket.
Risk Assessment
The risk involves potential local privilege escalation or system destabilization by an unprivileged user in deployments with disabled privilege separation (--disable-privsep) or where privsep initialization failed and the control socket operates in mode 0666.
Recommendation
Immediately update dhcpcd to a version containing commit 78ea09e (beyond 10.3.2) and enable privilege separation (privsep) in the configuration to mitigate the vulnerability.
Original NVD description (English source)
dhcpcd through 10.3.2, fixed in commit 78ea09e, contains a heap use-after-free vulnerability in the control socket handling within src/control.c that allows local unprivileged attackers to trigger memory corruption when privilege separation is disabled. Attackers can connect to the control socket and send a privileged command such as -x, causing control_recvdata() to free the client object while the same READ+HANGUP event subsequently reaches control_hangup() with the stale pointer, resulting in a use-after-free condition exploitable in deployments using --disable-privsep or where privsep initialization has failed with the control socket operating in mode 0666.