CVE-2026-56114

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.

Database specific

{
    "cna_assigner": "VulnCheck",
    "cwe_ids": [
        "CWE-787"
    ],
    "osv_generated_from": "https://github.com/CVEProject/cvelistV5/tree/main/cves/2026/56xxx/CVE-2026-56114.json"
}

References

Affected packages

Git / github.com/networkconfiguration/dhcpcd

Affected ranges

Type

GIT

Repo

https://github.com/networkconfiguration/dhcpcd

Events

Introduced

Fixed

2f00c7bfc408b6582d331932dfa47829c4819029

Database specific

Show details

{
    "cpe": "cpe:2.3:a:dhcpcd_project:dhcpcd:*:*:*:*:*:*:*:*",
    "extracted_events": [
        {
            "introduced": "0"
        },
        {
            "last_affected": "10.3.2"
        }
    ],
    "source": [
        "CPE_RANGE",
        "REFERENCES"
    ]
}

Affected versions

v10.*

v10.0.0

v10.0.1

v10.0.10

v10.0.2

v10.0.3

v10.0.4

v10.0.5

v10.0.6

v10.0.7

v10.0.8

v10.0.9

v10.1.0

v10.2.0

v10.2.1

v10.2.2

v10.2.3

v10.2.4

v10.3.0

v10.3.1

v10.3.2

v3.*

v3.2.3

v5.*

v5.0.1

v5.0.2

v5.0.3

v5.0.4

v5.0.5

v5.0.6

v5.1.0

v5.1.1

v5.1.2

v5.1.3

v5.1.4

v5.1.5

v5.2.0

v5.2.1

v5.2.10

v5.2.11

v5.2.12

v5.2.2

v5.2.3

v5.2.4

v5.2.6

v5.2.7

v5.2.9

v5.5.0

v5.5.1

v5.5.2

v5.5.3

v5.5.4

v5.5.5

v5.5.6

v5.6.0

v5.6.1

v5.6.2

v5.99.3

v5.99.6

v5.99.7

v6.*

v6.0.0

v6.0.1

v6.0.2

v6.0.3

v6.0.4

v6.0.5

v6.1.0

v6.10.0

v6.10.1

v6.10.2

v6.10.3

v6.11.0

v6.11.1

v6.11.2

v6.11.3

v6.2.0

v6.2.1

v6.3.0

v6.3.1

v6.3.2

v6.4.0

v6.4.1

v6.4.2

v6.4.3

v6.4.4

v6.4.5

v6.4.6

v6.4.7

v6.5.0

v6.5.1

v6.6.0

v6.6.1

v6.6.2

v6.6.3

v6.6.4

v6.6.5

v6.6.6

v6.6.7

v6.7.0

v6.7.1

v6.8.0

v6.8.1

v6.8.2

v6.9.0

v6.9.1

v6.9.2

v6.9.3

v6.9.4

v7.*

v7.0.0

v7.0.0-beta1

v7.0.0-beta2

v7.0.0-beta3

v7.0.0-rc1

v7.0.0-rc2

v7.0.0-rc3

v7.0.0-rc4

v7.0.1

v7.0.2

v7.0.3

v7.0.4

v7.0.5

v7.0.5a

v7.0.5b

v7.0.6

v7.0.7

v7.0.8

v7.1.0

v7.1.1

v8.*

v8.0.0

v8.0.1

v8.0.2

v8.0.3

v8.0.4

v8.0.5

v8.0.6

v8.1.0

v8.1.1

v8.1.2

v9.*

v9.0.0

v9.0.1

v9.0.2

v9.1.0

v9.1.1

v9.1.2

v9.1.3

v9.1.4

v9.2.0

v9.3.0

v9.3.1

v9.3.2

v9.3.3

v9.3.4

v9.4.0

Database specific

source

"https://storage.googleapis.com/cve-osv-conversion/osv-output/CVE-2026-56114.json"

vanir_signatures

[
    {
        "deprecated": false,
        "digest": {
            "function_hash": "69057622963740353441878516693269301419",
            "length": 11715
        },
        "id": "CVE-2026-56114-50a68a82",
        "signature_type": "Function",
        "signature_version": "v1",
        "source": "https://github.com/networkconfiguration/dhcpcd/commit/2f00c7bfc408b6582d331932dfa47829c4819029",
        "target": {
            "file": "src/dhcp6.c",
            "function": "dhcp6_makemessage"
        }
    },
    {
        "deprecated": false,
        "digest": {
            "line_hashes": [
                "304653931314822955258246815298936750684",
                "250140640461539026638967368857946588880",
                "252825014503037236579101255192920322128",
                "298040233048774608784223444967280714326"
            ],
            "threshold": 0.9
        },
        "id": "CVE-2026-56114-7439a70e",
        "signature_type": "Line",
        "signature_version": "v1",
        "source": "https://github.com/networkconfiguration/dhcpcd/commit/2f00c7bfc408b6582d331932dfa47829c4819029",
        "target": {
            "file": "src/dhcp6.c"
        }
    }
]

vanir_signatures_modified

"2026-08-27T08:33:00Z"