CVE-2026-56117

dhcpcd Heap Use-After-Free via Control Socket Handling

State
Published
Severity
5.7 Medium
Published
Jun 23, 2026
Updated
Jul 28, 2026
Reserved
Jun 18, 2026

Read the record on cve.org

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.

Scores

CVSSScoreVectorSource
4.05.7 MediumCVSS:4.0/AV:L/AC:L/AT:P/PR:L/UI:N/VC:N/VI:N/VA:H/SC:N/SI:N/SA:NVulnCheck
3.14.7 MediumCVSS:3.1/AV:L/AC:H/PR:L/UI:N/S:U/C:N/I:N/A:HVulnCheck

Weaknesses

Affected Products

ProductVersions
dhcpcdNetworkConfiguration
  • 10.3.2 and earlierAffected
  • 78ea09ed1633a583dbcde6e7bab9df4639ec8a34Not affected

References

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