CVE-2026-56114 | dhcpcd through 10.3.2, fixed in commit 2f00c7b, contains a o… | CVSS 5.3 MEDIUM

Description

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.

Metadata

CVE ID: CVE-2026-56114
State: PUBLISHED
Assigner: VulnCheck
Reserved: 2026-06-18 19:15 UTC
Published: 2026-06-23 16:08 UTC
Last updated: 2026-06-23 16:16 UTC
Primary CWE: CWE-787
Out-of-bounds Write
Vendor / Product: NetworkConfiguration / dhcpcd
Sources: cve.org · NVD

Severity & Metrics

5.3 MEDIUM CVSS 3.1

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

Affected products (1)

Vendor	Product	Platform	Versions
NetworkConfiguration	dhcpcd	—	0 ≤ 10.3.2, 2f00c7bfc408b6582d331932dfa47829c4819029

Weakness (CWE)

CWE	Source	Description
CWE-787	cna	Out-of-bounds Write

CVSS scores (2)

Score	Severity	Version	Source	Vector
6.0	MEDIUM	4.0	cna	CVSS:4.0/AV:A/AC:L/AT:P/PR:N/UI:N/VC:N/VI:N/VA:H/SC:N/SI:N/SA:N
5.3	MEDIUM	3.1	cna	CVSS:3.1/AV:A/AC:H/PR:N/UI:N/S:U/C:N/I:N/A:H

References (2)