CVE-2026-56117

Published: June 25, 2026Last modified: July 6, 2026

Description

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.

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References

• https://github.com/NetworkConfiguration/dhcpcd/commit/78ea09ed1633a583dbcde6e7bab9df4639ec8a34
• https://www.vulncheck.com/advisories/dhcpcd-heap-use-after-free-via-control-socket-handling