Medium
ntpsec — security advisory
Buffer overflow in NTPsec's Zyfer refclock allows local attacker to crash ntpd
- Products
- ntpsec
- Affected versions
- 1.0.0+dfsg1-1, 1.0.0+dfsg1-3, 1.1.0+dfsg1-1, 1.1.0+dfsg1-1ubuntu0.1, 1.1.0+dfsg1-1ubuntu0.2, 1.1.3+dfsg1-2, 1.1.7+dfsg1-1, 1.1.7+dfsg1-2, 1.1.8+dfsg1-1, 1.1.8+dfsg1-3, 1.1.8+dfsg1-4, 1.1.8+dfsg1-4build1, 1.2.0+dfsg1-4, 1.2.1+dfsg1-2, 1.2.1+dfsg1-3, 1.2.1+dfsg1-3ubuntu1, 1.2.1+dfsg1-4, 1.2.2+dfsg1-2, 1.2.2+dfsg1-3, 1.2.2+dfsg1-4, 1.2.2+dfsg1-4build1, 1.2.2+dfsg1-4build2, 1.2.3+dfsg1-8ubuntu1, 1.2.3+dfsg1-8ubuntu2, 1.2.3+dfsg1-8ubuntu3
- Fixed versions
- Not specified
- CVEs
- CVE-2026-18321
- Confirmed fixed CVEs
- Not specified
- Updated in this feed
- 31 Oct 2026, 02:55 UTC · Revision 1
Source evidence
Buffer overflow in NTPsec's Zyfer refclock allows local attacker to crash ntpd
osv:UBUNTU-CVE-2026-18321
ntpsec
Fixed versions: Not specified
ntpsec
Fixed versions: Not specified
ntpsec
Fixed versions: Not specified
ntpsec
Fixed versions: Not specified
ntpsec
Fixed versions: Not specified
ntpsec
Fixed versions: Not specified
Complete source record
{
"id": "c8c4cb7eca697487505d58c1b23ccc80cb27eba428e36ace312e111b0703097d",
"url": "https://osv.dev/vulnerability/UBUNTU-CVE-2026-18321",
"method": "structured",
"payload": {
"kind": "advisory",
"title": "UBUNTU-CVE-2026-18321",
"summary": "Buffer overflow in NTPsec's Zyfer refclock allows local attacker to crash ntpd",
"evidence": "osv:UBUNTU-CVE-2026-18321",
"products": [
{
"name": {
"value": "ntpsec",
"evidence": "/affected/0/package/name"
},
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"fixed_versions": [],
"affected_versions": [
{
"value": "1.0.0+dfsg1-1",
"evidence": "/affected/0/versions"
},
{
"value": "1.0.0+dfsg1-3",
"evidence": "/affected/0/versions"
},
{
"value": "1.1.0+dfsg1-1",
"evidence": "/affected/0/versions"
},
{
"value": "1.1.0+dfsg1-1ubuntu0.1",
"evidence": "/affected/0/versions"
},
{
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{
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{
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"evidence": "/affected/1/versions"
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{
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"evidence": "/affected/1/versions"
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{
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"evidence": "/affected/1/versions"
},
{
"value": "1.1.8+dfsg1-3",
"evidence": "/affected/1/versions"
},
{
"value": "1.1.8+dfsg1-4",
"evidence": "/affected/1/versions"
},
{
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"evidence": "/affected/1/versions"
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{
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"evidence": "/affected/2/versions"
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{
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"evidence": "/affected/2/versions"
},
{
"value": "1.2.1+dfsg1-3",
"evidence": "/affected/2/versions"
},
{
"value": "1.2.1+dfsg1-3ubuntu1",
"evidence": "/affected/2/versions"
},
{
"value": "1.2.1+dfsg1-4",
"evidence": "/affected/2/versions"
}
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},
{
"name": {
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"evidence": "/affected/3/package/name"
},
"prerequisites": [],
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"affected_versions": [
{
"value": "1.2.2+dfsg1-2",
"evidence": "/affected/3/versions"
},
{
"value": "1.2.2+dfsg1-3",
"evidence": "/affected/3/versions"
},
{
"value": "1.2.2+dfsg1-4",
"evidence": "/affected/3/versions"
},
{
"value": "1.2.2+dfsg1-4build1",
"evidence": "/affected/3/versions"
},
{
"value": "1.2.2+dfsg1-4build2",
"evidence": "/affected/3/versions"
}
]
},
{
"name": {
"value": "ntpsec",
"evidence": "/affected/4/package/name"
},
"prerequisites": [],
"fixed_versions": [],
"affected_versions": [
{
"value": "1.2.3+dfsg1-8ubuntu2",
"evidence": "/affected/4/versions"
},
{
"value": "1.2.3+dfsg1-8ubuntu3",
"evidence": "/affected/4/versions"
}
]
},
{
"name": {
"value": "ntpsec",
"evidence": "/affected/5/package/name"
},
"prerequisites": [],
"fixed_versions": [],
"affected_versions": [
{
"value": "1.2.3+dfsg1-8ubuntu1",
"evidence": "/affected/5/versions"
},
{
"value": "1.2.3+dfsg1-8ubuntu2",
"evidence": "/affected/5/versions"
}
]
}
],
"severity": "medium",
"structured": {
"id": "UBUNTU-CVE-2026-18321",
"aliases": [
"UBUNTU-CVE-2026-18321"
],
"metrics": [
{
"type": "CVSS_V3",
"score": "CVSS:3.1/AV:L/AC:H/PR:L/UI:N/S:U/C:N/I:N/A:H"
},
{
"type": "Ubuntu",
"score": "medium"
}
],
"affected": [
{
"ranges": [
{
"type": "ECOSYSTEM",
"events": [
{
"introduced": "0"
}
]
}
],
"package": {
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"purl": "pkg:deb/ubuntu/ntpsec?arch=source&distro=bionic",
"ecosystem": "Ubuntu:18.04:LTS"
},
"versions": [
"1.0.0+dfsg1-1",
"1.0.0+dfsg1-3",
"1.1.0+dfsg1-1",
"1.1.0+dfsg1-1ubuntu0.1",
"1.1.0+dfsg1-1ubuntu0.2"
],
"database_specific": {
"source": "https://github.com/canonical/ubuntu-security-notices/blob/main/osv/cve/2026/UBUNTU-CVE-2026-18321.json"
},
"ecosystem_specific": {
"binaries": [
{
"binary_name": "ntpsec",
"binary_version": "1.1.0+dfsg1-1ubuntu0.2"
},
{
"binary_name": "ntpsec-ntpdate",
"binary_version": "1.1.0+dfsg1-1ubuntu0.2"
},
{
"binary_name": "ntpsec-ntpviz",
"binary_version": "1.1.0+dfsg1-1ubuntu0.2"
},
{
"binary_name": "python3-ntp",
"binary_version": "1.1.0+dfsg1-1ubuntu0.2"
}
]
}
},
{
"ranges": [
{
"type": "ECOSYSTEM",
"events": [
{
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}
]
}
],
"package": {
"name": "ntpsec",
"purl": "pkg:deb/ubuntu/ntpsec?arch=source&distro=focal",
"ecosystem": "Ubuntu:20.04:LTS"
},
"versions": [
"1.1.3+dfsg1-2",
"1.1.7+dfsg1-1",
"1.1.7+dfsg1-2",
"1.1.8+dfsg1-1",
"1.1.8+dfsg1-3",
"1.1.8+dfsg1-4",
"1.1.8+dfsg1-4build1"
],
"database_specific": {
"source": "https://github.com/canonical/ubuntu-security-notices/blob/main/osv/cve/2026/UBUNTU-CVE-2026-18321.json"
},
"ecosystem_specific": {
"binaries": [
{
"binary_name": "ntpsec",
"binary_version": "1.1.8+dfsg1-4build1"
},
{
"binary_name": "ntpsec-ntpdate",
"binary_version": "1.1.8+dfsg1-4build1"
},
{
"binary_name": "ntpsec-ntpviz",
"binary_version": "1.1.8+dfsg1-4build1"
},
{
"binary_name": "python3-ntp",
"binary_version": "1.1.8+dfsg1-4build1"
}
]
}
},
{
"ranges": [
{
"type": "ECOSYSTEM",
"events": [
{
"introduced": "0"
}
]
}
],
"package": {
"name": "ntpsec",
"purl": "pkg:deb/ubuntu/ntpsec?arch=source&distro=jammy",
"ecosystem": "Ubuntu:22.04:LTS"
},
"versions": [
"1.2.0+dfsg1-4",
"1.2.1+dfsg1-2",
"1.2.1+dfsg1-3",
"1.2.1+dfsg1-3ubuntu1",
"1.2.1+dfsg1-4"
],
"database_specific": {
"source": "https://github.com/canonical/ubuntu-security-notices/blob/main/osv/cve/2026/UBUNTU-CVE-2026-18321.json"
},
"ecosystem_specific": {
"binaries": [
{
"binary_name": "ntpsec",
"binary_version": "1.2.1+dfsg1-4"
},
{
"binary_name": "ntpsec-ntpdate",
"binary_version": "1.2.1+dfsg1-4"
},
{
"binary_name": "ntpsec-ntpviz",
"binary_version": "1.2.1+dfsg1-4"
},
{
"binary_name": "python3-ntp",
"binary_version": "1.2.1+dfsg1-4"
}
]
}
},
{
"ranges": [
{
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{
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}
]
}
],
"package": {
"name": "ntpsec",
"purl": "pkg:deb/ubuntu/ntpsec?arch=source&distro=noble",
"ecosystem": "Ubuntu:24.04:LTS"
},
"versions": [
"1.2.2+dfsg1-2",
"1.2.2+dfsg1-3",
"1.2.2+dfsg1-4",
"1.2.2+dfsg1-4build1",
"1.2.2+dfsg1-4build2"
],
"database_specific": {
"source": "https://github.com/canonical/ubuntu-security-notices/blob/main/osv/cve/2026/UBUNTU-CVE-2026-18321.json"
},
"ecosystem_specific": {
"binaries": [
{
"binary_name": "ntp",
"binary_version": "1:4.2.8p15+dfsg-2~1.2.2+dfsg1-4build2"
},
{
"binary_name": "ntpdate",
"binary_version": "1:4.2.8p15+dfsg-2~1.2.2+dfsg1-4build2"
},
{
"binary_name": "ntpsec",
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{
"binary_name": "ntpsec-ntpdate",
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{
"binary_name": "ntpsec-ntpdig",
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},
{
"binary_name": "ntpsec-ntpviz",
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},
{
"binary_name": "python3-ntp",
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{
"binary_name": "sntp",
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{
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"ecosystem": "Ubuntu:26.10"
},
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{
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},
{
"binary_name": "ntpsec-ntpdate",
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},
{
"binary_name": "ntpsec-ntpdig",
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},
{
"binary_name": "ntpsec-ntpviz",
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}
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}
},
{
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],
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"purl": "pkg:deb/ubuntu/ntpsec?arch=source&distro=resolute",
"ecosystem": "Ubuntu:26.04:LTS"
},
"versions": [
"1.2.3+dfsg1-8ubuntu1",
"1.2.3+dfsg1-8ubuntu2"
],
"database_specific": {
"source": "https://github.com/canonical/ubuntu-security-notices/blob/main/osv/cve/2026/UBUNTU-CVE-2026-18321.json"
},
"ecosystem_specific": {
"binaries": [
{
"binary_name": "ntpsec",
"binary_version": "1.2.3+dfsg1-8ubuntu2"
},
{
"binary_name": "ntpsec-ntpdate",
"binary_version": "1.2.3+dfsg1-8ubuntu2"
},
{
"binary_name": "ntpsec-ntpdig",
"binary_version": "1.2.3+dfsg1-8ubuntu2"
},
{
"binary_name": "ntpsec-ntpviz",
"binary_version": "1.2.3+dfsg1-8ubuntu2"
},
{
"binary_name": "python3-ntp",
"binary_version": "1.2.3+dfsg1-8ubuntu2"
}
]
}
}
],
"modified": "2026-10-17T12:59:53.377476925Z",
"provider": "osv",
"upstream": [
"CVE-2026-18321"
],
"references": [
"https://ubuntu.com/security/CVE-2026-18321",
"https://www.cve.org/CVERecord?id=CVE-2026-18321",
"https://gitlab.com/NTPsec/ntpsec/-/work_items/890"
]
},
"related_cves": [
{
"value": "CVE-2026-18321",
"evidence": "/upstream"
}
],
"security_relevant": true,
"severity_evidence": "/severity/0/score"
},
"source_id": "core-osv",
"document_id": 359871,
"published_at": "2026-07-31T19:17:00+00:00"
}