CVE-2026-56117

medium

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.

References

https://www.vulncheck.com/advisories/dhcpcd-heap-use-after-free-via-control-socket-handling

https://github.com/NetworkConfiguration/dhcpcd/commit/78ea09ed1633a583dbcde6e7bab9df4639ec8a34

Details

Source: Mitre, NVD

Published: 2026-06-23

Updated: 2026-06-23

Risk Information

CVSS v2

Base Score: 3.8

Vector: CVSS2#AV:L/AC:H/Au:S/C:N/I:N/A:C

Severity: Low

CVSS v3

Base Score: 4.7

Vector: CVSS:3.1/AV:L/AC:H/PR:L/UI:N/S:U/C:N/I:N/A:H

Severity: Medium

CVSS v4

Base Score: 5.7

Vector: CVSS:4.0/AV:L/AC:L/AT:P/PR:L/UI:N/VC:N/VI:N/VA:H/SC:N/SI:N/SA:N

Severity: Medium