CVE-2026-56114
6.5
MEDIUM
CVSS 3.1
EPSS 0.18%
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.
How to fix CVE-2026-56114
To remediate CVE-2026-56114, upgrade the affected package to a fixed version below.
- —upgrade to 1:10.1.0-11+deb13u3 or later
- —upgrade to 7.1.0-2+deb11u1 or later
Is CVE-2026-56114 being exploited?
Low — EPSS is 0.2%, meaning exploitation activity has not been observed at scale.
Affected packages (2)
- from 0, < 1:10.1.0-11+deb13u3
- from 0, < 7.1.0-2+deb11u1
CVSS scores
| Source | Version | Severity | Vector |
|---|---|---|---|
| osv | CVSS 3.1 | MEDIUM6.5 | CVSS:3.1/AV:A/AC:L/PR:N/UI:N/S:U/C:N/I:N/A:H |