CVE-2026-56113

dhcpcd through 10.3.2, fixed in commit 5733d3c, contains a heap use-after-free vulnerability that allows unauthenticated same-link attackers to crash the daemon by sending a crafted DHCPv6 RENEW reply with RFC6603 OPTIONPDEXCLUDE and both preferred and valid lifetimes set to zero. Attackers acting as or impersonating a DHCPv6 server can trigger dhcp6deprecatedele() to free a delegated child address while an outer TAILQFOREACHSAFE iterator in dhcp6deprecateaddrs() still holds the freed pointer, causing a use-after-free when TAILQ_REMOVE is reached.

Database specific

{
    "cna_assigner": "VulnCheck",
    "cwe_ids": [
        "CWE-416"
    ],
    "osv_generated_from": "https://github.com/CVEProject/cvelistV5/tree/main/cves/2026/56xxx/CVE-2026-56113.json"
}

References

Affected packages

Git / github.com/networkconfiguration/dhcpcd

Affected ranges

Type

GIT

Repo

https://github.com/networkconfiguration/dhcpcd

Events

Introduced

Fixed

5733d3c59a5651f64357ac11c98b4f39895c8d25

Database specific

Show details

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

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-2026-56113.json"

vanir_signatures

[
    {
        "target": {
            "function": "dhcp6_deprecateaddrs",
            "file": "src/dhcp6.c"
        },
        "deprecated": false,
        "source": "https://github.com/networkconfiguration/dhcpcd/commit/5733d3c59a5651f64357ac11c98b4f39895c8d25",
        "id": "CVE-2026-56113-2f533bcb",
        "signature_version": "v1",
        "digest": {
            "length": 855.0,
            "function_hash": "38217836670330965262671375723284649936"
        },
        "signature_type": "Function"
    },
    {
        "target": {
            "file": "src/dhcp6.c"
        },
        "deprecated": false,
        "source": "https://github.com/networkconfiguration/dhcpcd/commit/5733d3c59a5651f64357ac11c98b4f39895c8d25",
        "id": "CVE-2026-56113-abbebfbc",
        "signature_version": "v1",
        "digest": {
            "threshold": 0.9,
            "line_hashes": [
                "136816508761598400985543780295057781085",
                "70116549642961668225413951985088455453",
                "334129743086100125299628836777090465900",
                "65163220616945559423554464179356445373",
                "235175126219071773954648722181992834413",
                "134871184953256908819627369364717691037",
                "186307261440675469596514055327885841911",
                "57596693776431650072987208320667416699",
                "263233540540241997255220069492180439265",
                "149792847346994764372582313324334145432",
                "12482571540594411009898108286194928805",
                "103764026704857163783464042453824251451",
                "64139564256525267409866191545511751858",
                "70403780905678577280422405411882858995",
                "306066193874790716893525013149446564128",
                "305407463024304548130196606906410878762",
                "196738821433478305689365503664778699221",
                "42171260437955482228791058259897556416",
                "102914474885341466931480028899353746678",
                "268315079292349240806989298369761762059",
                "14496147764778323022595565968215539408",
                "238332297913012442468328728073093072441",
                "249260016317298460207765854401007700624",
                "222241949908639040467391967172357249078",
                "194702165493428383466885428272609286903",
                "46650817038198684612690591605158789523",
                "302769553296557768676732677030229525503",
                "266386384329346193554282574394465006975",
                "336953781359911694556887833470062412440"
            ]
        },
        "signature_type": "Line"
    },
    {
        "target": {
            "function": "dhcp6_deprecatedele",
            "file": "src/dhcp6.c"
        },
        "deprecated": false,
        "source": "https://github.com/networkconfiguration/dhcpcd/commit/5733d3c59a5651f64357ac11c98b4f39895c8d25",
        "id": "CVE-2026-56113-eb66bb78",
        "signature_version": "v1",
        "digest": {
            "length": 741.0,
            "function_hash": "71411627330105937576131378872413247121"
        },
        "signature_type": "Function"
    }
]

vanir_signatures_modified

"2026-08-12T16:09:49Z"