CVE-2026-56113: Dhcpcd Project Dhcpcd

Medium severity, CVSS 6.5. EPSS: 0.3% chance of exploitation in the next 30 days.

dhcpcd through 10.3.2, fixed in commit 5733d3c, contains a heap use-after-free vulnerability that allows unauthenticated same-link attackers to crash the daemon by sending a crafted DHCPv6 RENEW reply with RFC6603 OPTION_PD_EXCLUDE and both preferred and valid lifetimes set to zero. Attackers acting as or impersonating a DHCPv6 server can trigger dhcp6_deprecatedele() to free a delegated child address while an outer TAILQ_FOREACH_SAFE iterator in dhcp6_deprecateaddrs() still holds the freed pointer, causing a use-after-free when TAILQ_REMOVE is reached.

Affected products

• Dhcpcd Project Dhcpcd: up to and including 10.3.2

Published 2026-06-23. Last modified 2026-07-14.