CVE-2026-56114

MEDIUM
MEDIUM Priority: 0.02 BB Relevance: 57/100
Published: 2026-06-23 Modified: 2026-10-25 First seen: 2026-10-29 Status: active

Attack Surface

Adjacent Low Complexity No Auth No Interaction

CVSS Vector Breakdown

AV: Adjacent
AC: Low
PR: None
UI: None
S: X
AT: Present
VC: None
VI: None
VA: High

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.

Weakness Classification (1)

Affected Software (1)

VendorProductVersion
dhcpcd_project dhcpcd < 10.3.2

Bug Bounty Relevance

57 / 100
✓ No authentication
✓ Low complexity
✓ No user interaction

CVSS Score

6.0 / 10.0 v4.0
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/E:X/CR:X/IR:X/AR:X/MAV:X/MAC:X/MAT:X/MPR:X/MUI:X/MVC:X/MVI:X/MVA:X/MSC:X/MSI:X/MSA:X/S:X/AU:X/R:X/V:X/RE:X/U:X

EPSS — Exploitation Probability

0.27%
Raw Score 0.002690
Percentile 19.1%
Date 2026-10-29

EPSS Trend

2026-10-29
0.00269
2026-10-28
0.00269

Intelligence Sources

nvd ref →