PT-2026-51564 · Networkconfiguration · Dhcpcd

Cub3Y0Nd + 1 · Published 2026-06-23 · Updated 2026-06-23 · CVE-2026-56115

Mitre

CVSS v3.1

5.3

Medium

Base vector

AV:A/AC:H/PR:N/UI:N/S:U/C:N/I:N/A:H

dhcpcd through 10.3.2, fixed in commit 2f00c7b, contains a one-byte stack out-of-bounds write vulnerability in dhcp6 makemessage() in src/dhcp6.c that allows unauthenticated same-link attackers to write beyond a fixed local buffer by serializing an oversized RFC6603 OPTION PD EXCLUDE option body. Attackers can send a crafted DHCPv6 ADVERTISE message containing an IA PD IAPREFIX /0 with a valid OPTION PD EXCLUDE using an exclude prefix length of /121 through /128 to trigger the out-of-bounds write and potentially corrupt adjacent stack memory.

Fix

Memory Corruption

Weakness Enumeration

CWE-787

Related Identifiers

CVE-2026-56115

Affected Products

Dhcpcd

References · 3

• https://github.com/NetworkConfiguration/dhcpcd/commit/2f00c7bfc408b6582d331932dfa47829c4819029 · Patch
• https://nvd.nist.gov/vuln/detail/CVE-2026-56115 · Security Note
• https://vulncheck.com/advisories/dhcpcd-stack-out-of-bounds-write-in-dhcp6-makemessage · Note