CVE-2026-56115
MEDIUM EPSS 22.3%
Published Jun 23, 20261w ago · Modified Jun 23, 20261w ago
6.0 CVSS 4.0
Published Jun 23, 2026 1w ago
Last Modified Jun 23, 2026 1w ago
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.
CVSS Details
Base Score
Exploitability
Impact
Vector string
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 Attack Vector Adjacent
Attack Complexity Low
Privileges Required None
User Interaction None
Scope X
Threat Intelligence
EPSS Exploit Probability
22.3% percentile
Exploit & Patch Status
No Known Exploit
No Patch Available
Weaknesses 1
CWE-787 Out-of-bounds Write Memory Safety
References 2
- github.com https://github.com/NetworkConfiguration/dhcpcd/commit/2f00c7bfc408b6582d331932dfa47829c4819029
- vulncheck.com https://www.vulncheck.com/advisories/dhcpcd-stack-out-of-bounds-write-in-dhcp6-makemessage
Remediation
No remediation data recorded yet
Check vendor advisories and the NVD entry for patch availability.