CVE-2026-56116

dhcpcd through 10.3.2, fixed in commit 708b4a5, contains a memory leak vulnerability in the IPv6 Router Advertisement route information handling that allows an unauthenticated same-link attacker to cause denial of service by sending crafted Router Advertisements. Attackers can repeatedly send Router Advertisements containing Route Information options with a lifetime of zero, triggering unfreed allocations in routeinfo_findalloc() that cause linear memory exhaustion and eventual daemon crash.

CVSS 4.0

7.1CVSS:4.0/AV:A/AC:L/AT:N/PR:N/UI:N/VC:N/VI:N/VA:H/SC:N/SI:N/SA:N

CVSS 3.1

6.5CVSS:3.1/AV:A/AC:L/PR:N/UI:N/S:U/C:N/I:N/A:H

EPSS

0.3% chance of exploitation in the next 30 days; higher than 21% of CVEs (scores of 2026-10-25)

CWE

CWE-401

Published

2026-06-23

Modified

2026-10-25

Record from

the NVD, synced 2026-10-25

Affected

• dhcpcd_project:dhcpcd

References

• https://github.com/NetworkConfiguration/dhcpcd/commit/708b4a56bae080a5b18c2e0c4c6fbe103131a2b0
• https://www.vulncheck.com/advisories/dhcpcd-memory-leak-dos-via-ipv6-router-advertisement-handling

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