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OpenAdvisories
Medium · 6.5 CVE-2026-56116 EUVD-2026-38496GHSA-g36w-q35r-qvg3

dhcpcd Memory Leak DoS via IPv6 Router Advertisement Handling

Published Jun 23, 2026 · Updated Jul 28, 2026 · Assigned by VulnCheck

Description

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.

Affected products

VendorProductAffectedFixed
NetworkConfiguration dhcpcd 10.0.7 – ≤ 10.3.2 —

Fixed in Linux distributions

Distributions backport fixes, so the version that fixes this vulnerability differs per release — upgrade to at least the version shown. From the distributions' security trackers and advisories.

ReleasePackageFixed inAdvisory
Debian 14 dhcpcd 1:10.3.2-4 —
Debian 13 dhcpcd 1:10.1.0-11+deb13u3 —
ReleasePackageFixed inAdvisory
Ubuntu 26.04 LTS dhcpcd No fix yet —
Ubuntu 25.10 dhcpcd No fix yet —
ReleasePackageFixed inAdvisory
SLES for SAP 16.0 dhcpcd 10.5.0-160000.1.1 SUSE-SU-2026:23562-1
SLES 16.0 dhcpcd 10.5.0-160000.1.1 SUSE-SU-2026:23562-1
SLE Micro 6.2 dhcpcd 10.5.0-160000.1.1 SUSE-SU-2026:23400-1
ReleasePackageFixed inAdvisory
openSUSE Tumbleweed dhcpcd 10.5.0-1.1 openSUSE-SU-2026:11473-1
openSUSE Leap 16.0 dhcpcd 10.5.0-160000.1.1 openSUSE-SU-2026:21692-1
ReleasePackageFixed inAdvisory
Alpine v3.24 dhcpcd 10.5.2-r0 —
Alpine v3.23 dhcpcd 10.5.2-r0 —

Azure Linux

ReleasePackageFixed inAdvisory
Azure Linux 3 dhcpcd 10.0.8-2 —

Advisories 5

References