CVE-2026-42944

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Source
https://cve.org/CVERecord?id=CVE-2026-42944
Import Source
https://storage.googleapis.com/osv-test-cve-osv-conversion/osv-output/CVE-2026-42944.json
JSON Data
https://api.test.osv.dev/v1/vulns/CVE-2026-42944
Downstream
Related
Published
2026-05-20T10:16:27.760Z
Modified
2026-06-11T16:14:05.590835757Z
Severity
  • 7.5 (High) CVSS_V3 - CVSS:3.1/AV:N/AC:L/PR:N/UI:N/S:U/C:N/I:N/A:H CVSS Calculator
Summary
[none]
Details

NLnet Labs Unbound 1.14.0 up to and including version 1.25.0 has a vulnerability that results in heap overflow when encoding multiple NSID and/or DNS Cookie EDNS and/or EDNS Padding options in the reply packet. The relevant options ('nsid', 'answer-cookie', 'pad-responses' (default)) need to be enabled for the vulnerability to be exploited. An adversary who can query Unbound can exploit the vulnerability by attaching multiple NSID and/or DNS Cookie EDNS and/or EDNS Padding options to the query. A flaw in the size calculation of the EDNS field truncates the correct value which allows the encoder to overflow the available space when writing. Those two combined lead to a heap overflow write of Unbound controlled data and eventually a crash. Unbound 1.25.1 contains a patch with a fix to de-duplicate the EDNS options and a fix to prevent truncation of the EDNS field size calculation.

References

Affected packages

Git / github.com/nlnetlabs/unbound

Affected ranges

Type
GIT
Repo
https://github.com/nlnetlabs/unbound
Events
Introduced
919c8c9527281a7289415c00f8f2aed12b17a9aa
Fixed
75b6dba593d4fff000434cd64807c6ebd50bd244
Database specific 
{
    "extracted_events": [
        {
            "introduced": "1.14.0"
        },
        {
            "fixed": "1.25.1"
        }
    ],
    "cpe": "cpe:2.3:a:nlnetlabs:unbound:*:*:*:*:*:*:*:*",
    "source": "CPE_RANGE"
}

Affected versions

release-1.*
release-1.14.0
release-1.14.0rc1
release-1.15.0
release-1.15.0rc1
release-1.16.0
release-1.16.0rc1
release-1.16.1
release-1.16.1rc1
release-1.16.2
release-1.18.0
release-1.18.0rc1
release-1.19.0
release-1.19.0rc1
release-1.19.3rc1
release-1.20.0
release-1.20.0rc1
release-1.21.0
release-1.21.0rc1
release-1.22.0
release-1.22.0rc1
release-1.23.0rc1
release-1.24.0
release-1.24.0rc1
release-1.25.0
release-1.25.0rc1

Database specific

vanir_signatures 
[
    {
        "digest": {
            "length": 1502.0,
            "function_hash": "26148135886169857913239956572075736548"
        },
        "id": "CVE-2026-42944-7cb89fac",
        "signature_version": "v1",
        "target": {
            "file": "services/rpz.c",
            "function": "rpz_callback_from_iterator_module"
        },
        "deprecated": false,
        "signature_type": "Function",
        "source": "https://github.com/nlnetlabs/unbound/commit/75b6dba593d4fff000434cd64807c6ebd50bd244"
    },
    {
        "digest": {
            "line_hashes": [
                "108481287081154918060659085654141150584",
                "73953166938600086918224773195867549742",
                "15251087855327528788980657535362970158",
                "48532896601082718174781974683716349061",
                "287248990686482337183326495344180868363",
                "112058947495561481565691171486557666856",
                "238258467286774268681997190612827183971",
                "126648031849056156900266153546629664662",
                "335401097143186200364020904286165936708",
                "336096779053276656395004922884987906159",
                "248876396313049466881138460638611830858",
                "293135123655960925553682804594622081358",
                "298612071867479354827766089224387452786",
                "217265304546593372824910550975155656654",
                "13292601781282786772501437491204364169",
                "281286782737850123600796590480125479595",
                "74511316679551775089931390035715335201",
                "161066344018382590627892027575409612852",
                "226343512543910522766563315515650712879"
            ],
            "threshold": 0.9
        },
        "id": "CVE-2026-42944-a3b17d2e",
        "signature_version": "v1",
        "target": {
            "file": "services/rpz.c"
        },
        "deprecated": false,
        "signature_type": "Line",
        "source": "https://github.com/nlnetlabs/unbound/commit/75b6dba593d4fff000434cd64807c6ebd50bd244"
    }
]
vanir_signatures_modified 
"2026-06-02T08:21:51Z"
source 
"https://storage.googleapis.com/osv-test-cve-osv-conversion/osv-output/CVE-2026-42944.json"