CVE-2026-56115
dhcpcd Stack Out-of-Bounds Write in dhcp6_makemessage()
CVSS Score
5.3
EPSS Score
0.0%
EPSS Percentile
0th
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.
| CWE | CWE-787 |
| Vendor | networkconfiguration |
| Product | dhcpcd |
| Published | Jun 23, 2026 |
| Last Updated | Jun 23, 2026 |
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CVSS v3 Breakdown
CVSS:3.1/AV:A/AC:H/PR:N/UI:N/S:U/C:N/I:N/A:H Attack Vector
Adjacent
Attack Complexity
High
Privileges Required
None
User Interaction
None
Scope
Unchanged
Confidentiality
None
Integrity
None
Availability
High
Affected Versions
NetworkConfiguration / dhcpcd
0 ≤ 10.3.2
References
Credits
CuB3y0nd VulnCheck