dhcpcd Stack Out-of-Bounds Write in dhcp6_makemessage()_CVE-2026-56115

6 / 10

MEDIUM

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

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.

Basic Information

ID CVE-2026-56115

Source VulnCheck

Published Jun 23, 2026 at 16:08

Modified Jun 23, 2026 at 17:08

Affected Product

Vendor NetworkConfiguration

Product dhcpcd

Affected Versions NetworkConfiguration dhcpcd 0

CWE Classification

CWE-787

References

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    "published": "2026-06-23T16:08:55.358Z",
    "modified": "2026-06-23T17:08:40.406Z",
    "type": "cve",
    "title": "dhcpcd Stack Out-of-Bounds Write in dhcp6_makemessage()",
    "source": "VulnCheck",
    "references": "https://github.com/NetworkConfiguration/dhcpcd/commit/2f00c7bfc408b6582d331932dfa47829c4819029\nhttps://www.vulncheck.com/advisories/dhcpcd-stack-out-of-bounds-write-in-dhcp6-makemessage",
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    "cvss": {
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