HighFix available
unbound — security advisory
Unbound before 1.10.1 has Insufficient Control of Network Message Volume, aka an "NXNSAttack" issue. This is triggered by random subdomains in the NSDNAME in NS records.
- Products
- unbound
- Affected versions
- 1.4.20-1, 1.4.21-1, 1.4.21-1ubuntu1, 1.4.21-1ubuntu2, 1.4.22-1ubuntu1, 1.4.22-1ubuntu2, 1.4.22-1ubuntu3, 1.4.22-1ubuntu4, 1.4.22-1ubuntu4.14.04.1, 1.4.22-1ubuntu4.14.04.2, 1.4.22-1ubuntu4.14.04.3, 1.4.22-1ubuntu4.14.04.3+esm1, 1.4.22-1ubuntu4.14.04.3+esm2, 1.4.22-1ubuntu4.14.04.3+esm3, 1.4.22-1ubuntu4.14.04.3+esm4, 1.4.22-1ubuntu4.14.04.3+esm5, 1.4.22-1ubuntu6, 1.5.7-1ubuntu1, 1.5.7-1ubuntu2, 1.5.8-1ubuntu1, 1.5.8-1ubuntu1.1, 1.5.8-1ubuntu1.1+esm1, 1.5.8-1ubuntu1.1+esm2, 1.5.8-1ubuntu1.1+esm3, 1.5.8-1ubuntu1.1+esm4, 1.5.8-1ubuntu1.1+esm5, 1.6.5-1, 1.6.7-1, 1.6.7-1build1, 1.6.7-1ubuntu1, 1.6.7-1ubuntu2, 1.6.7-1ubuntu2.1, 1.6.7-1ubuntu2.2, 1.9.0-2ubuntu1, 1.9.0-2ubuntu2, 1.9.4-2, 1.9.4-2ubuntu1
- Fixed versions
- 1.6.7-1ubuntu2.3, 1.9.4-2ubuntu1.1
- CVEs
- CVE-2020-12662
- Confirmed fixed CVEs
- Not specified
- Updated in this feed
- 31 Oct 2026, 14:34 UTC · Revision 1
Source evidence
Unbound before 1.10.1 has Insufficient Control of Network Message Volume, aka an "NXNSAttack" issue. This is triggered by random subdomains in the NSDNAME in NS records.
osv:UBUNTU-CVE-2020-12662
unbound
Fixed versions: Not specified
unbound
Fixed versions: Not specified
unbound
Fixed versions: 1.6.7-1ubuntu2.3
unbound
Fixed versions: 1.9.4-2ubuntu1.1
Complete source record
{
"id": "43ffc9e45b93f7b24c77d5a6adf417a017e50dbb1ee7b29543bc2cb99864973f",
"url": "https://osv.dev/vulnerability/UBUNTU-CVE-2020-12662",
"method": "structured",
"payload": {
"kind": "advisory",
"title": "UBUNTU-CVE-2020-12662",
"summary": "Unbound before 1.10.1 has Insufficient Control of Network Message Volume, aka an \"NXNSAttack\" issue. This is triggered by random subdomains in the NSDNAME in NS records.",
"evidence": "osv:UBUNTU-CVE-2020-12662",
"products": [
{
"name": {
"value": "unbound",
"evidence": "/affected/0/package/name"
},
"prerequisites": [],
"fixed_versions": [],
"affected_versions": [
{
"value": "1.4.20-1",
"evidence": "/affected/0/versions"
},
{
"value": "1.4.21-1",
"evidence": "/affected/0/versions"
},
{
"value": "1.4.21-1ubuntu1",
"evidence": "/affected/0/versions"
},
{
"value": "1.4.21-1ubuntu2",
"evidence": "/affected/0/versions"
},
{
"value": "1.4.22-1ubuntu1",
"evidence": "/affected/0/versions"
},
{
"value": "1.4.22-1ubuntu2",
"evidence": "/affected/0/versions"
},
{
"value": "1.4.22-1ubuntu3",
"evidence": "/affected/0/versions"
},
{
"value": "1.4.22-1ubuntu4",
"evidence": "/affected/0/versions"
},
{
"value": "1.4.22-1ubuntu4.14.04.1",
"evidence": "/affected/0/versions"
},
{
"value": "1.4.22-1ubuntu4.14.04.2",
"evidence": "/affected/0/versions"
},
{
"value": "1.4.22-1ubuntu4.14.04.3",
"evidence": "/affected/0/versions"
},
{
"value": "1.4.22-1ubuntu4.14.04.3+esm1",
"evidence": "/affected/0/versions"
},
{
"value": "1.4.22-1ubuntu4.14.04.3+esm2",
"evidence": "/affected/0/versions"
},
{
"value": "1.4.22-1ubuntu4.14.04.3+esm3",
"evidence": "/affected/0/versions"
},
{
"value": "1.4.22-1ubuntu4.14.04.3+esm4",
"evidence": "/affected/0/versions"
},
{
"value": "1.4.22-1ubuntu4.14.04.3+esm5",
"evidence": "/affected/0/versions"
}
]
},
{
"name": {
"value": "unbound",
"evidence": "/affected/1/package/name"
},
"prerequisites": [],
"fixed_versions": [],
"affected_versions": [
{
"value": "1.4.22-1ubuntu6",
"evidence": "/affected/1/versions"
},
{
"value": "1.5.7-1ubuntu1",
"evidence": "/affected/1/versions"
},
{
"value": "1.5.7-1ubuntu2",
"evidence": "/affected/1/versions"
},
{
"value": "1.5.8-1ubuntu1",
"evidence": "/affected/1/versions"
},
{
"value": "1.5.8-1ubuntu1.1",
"evidence": "/affected/1/versions"
},
{
"value": "1.5.8-1ubuntu1.1+esm1",
"evidence": "/affected/1/versions"
},
{
"value": "1.5.8-1ubuntu1.1+esm2",
"evidence": "/affected/1/versions"
},
{
"value": "1.5.8-1ubuntu1.1+esm3",
"evidence": "/affected/1/versions"
},
{
"value": "1.5.8-1ubuntu1.1+esm4",
"evidence": "/affected/1/versions"
},
{
"value": "1.5.8-1ubuntu1.1+esm5",
"evidence": "/affected/1/versions"
}
]
},
{
"name": {
"value": "unbound",
"evidence": "/affected/2/package/name"
},
"prerequisites": [],
"fixed_versions": [
{
"value": "1.6.7-1ubuntu2.3",
"evidence": "/affected/2/ranges"
}
],
"affected_versions": [
{
"value": "1.6.5-1",
"evidence": "/affected/2/versions"
},
{
"value": "1.6.7-1",
"evidence": "/affected/2/versions"
},
{
"value": "1.6.7-1build1",
"evidence": "/affected/2/versions"
},
{
"value": "1.6.7-1ubuntu1",
"evidence": "/affected/2/versions"
},
{
"value": "1.6.7-1ubuntu2",
"evidence": "/affected/2/versions"
},
{
"value": "1.6.7-1ubuntu2.1",
"evidence": "/affected/2/versions"
},
{
"value": "1.6.7-1ubuntu2.2",
"evidence": "/affected/2/versions"
}
]
},
{
"name": {
"value": "unbound",
"evidence": "/affected/3/package/name"
},
"prerequisites": [],
"fixed_versions": [
{
"value": "1.9.4-2ubuntu1.1",
"evidence": "/affected/3/ranges"
}
],
"affected_versions": [
{
"value": "1.9.0-2ubuntu1",
"evidence": "/affected/3/versions"
},
{
"value": "1.9.0-2ubuntu2",
"evidence": "/affected/3/versions"
},
{
"value": "1.9.4-2",
"evidence": "/affected/3/versions"
},
{
"value": "1.9.4-2ubuntu1",
"evidence": "/affected/3/versions"
}
]
}
],
"severity": "high",
"structured": {
"id": "UBUNTU-CVE-2020-12662",
"aliases": [
"UBUNTU-CVE-2020-12662"
],
"metrics": [
{
"type": "CVSS_V3",
"score": "CVSS:3.1/AV:N/AC:L/PR:N/UI:N/S:U/C:N/I:N/A:H"
},
{
"type": "Ubuntu",
"score": "medium"
}
],
"affected": [
{
"ranges": [
{
"type": "ECOSYSTEM",
"events": [
{
"introduced": "0"
}
]
}
],
"package": {
"name": "unbound",
"purl": "pkg:deb/ubuntu/unbound?arch=source&distro=esm-infra-legacy%2Ftrusty",
"ecosystem": "Ubuntu:Pro:14.04:LTS"
},
"versions": [
"1.4.20-1",
"1.4.21-1",
"1.4.21-1ubuntu1",
"1.4.21-1ubuntu2",
"1.4.22-1ubuntu1",
"1.4.22-1ubuntu2",
"1.4.22-1ubuntu3",
"1.4.22-1ubuntu4",
"1.4.22-1ubuntu4.14.04.1",
"1.4.22-1ubuntu4.14.04.2",
"1.4.22-1ubuntu4.14.04.3",
"1.4.22-1ubuntu4.14.04.3+esm1",
"1.4.22-1ubuntu4.14.04.3+esm2",
"1.4.22-1ubuntu4.14.04.3+esm3",
"1.4.22-1ubuntu4.14.04.3+esm4",
"1.4.22-1ubuntu4.14.04.3+esm5"
],
"database_specific": {
"source": "https://github.com/canonical/ubuntu-security-notices/blob/main/osv/cve/2020/UBUNTU-CVE-2020-12662.json"
},
"ecosystem_specific": {
"binaries": [
{
"binary_name": "libunbound2",
"binary_version": "1.4.22-1ubuntu4.14.04.3+esm5"
},
{
"binary_name": "python-unbound",
"binary_version": "1.4.22-1ubuntu4.14.04.3+esm5"
},
{
"binary_name": "unbound",
"binary_version": "1.4.22-1ubuntu4.14.04.3+esm5"
},
{
"binary_name": "unbound-anchor",
"binary_version": "1.4.22-1ubuntu4.14.04.3+esm5"
},
{
"binary_name": "unbound-host",
"binary_version": "1.4.22-1ubuntu4.14.04.3+esm5"
}
]
}
},
{
"ranges": [
{
"type": "ECOSYSTEM",
"events": [
{
"introduced": "0"
}
]
}
],
"package": {
"name": "unbound",
"purl": "pkg:deb/ubuntu/unbound?arch=source&distro=esm-infra-legacy%2Fxenial",
"ecosystem": "Ubuntu:Pro:16.04:LTS"
},
"versions": [
"1.4.22-1ubuntu6",
"1.5.7-1ubuntu1",
"1.5.7-1ubuntu2",
"1.5.8-1ubuntu1",
"1.5.8-1ubuntu1.1",
"1.5.8-1ubuntu1.1+esm1",
"1.5.8-1ubuntu1.1+esm2",
"1.5.8-1ubuntu1.1+esm3",
"1.5.8-1ubuntu1.1+esm4",
"1.5.8-1ubuntu1.1+esm5"
],
"database_specific": {
"source": "https://github.com/canonical/ubuntu-security-notices/blob/main/osv/cve/2020/UBUNTU-CVE-2020-12662.json"
},
"ecosystem_specific": {
"binaries": [
{
"binary_name": "libunbound2",
"binary_version": "1.5.8-1ubuntu1.1+esm5"
},
{
"binary_name": "python-unbound",
"binary_version": "1.5.8-1ubuntu1.1+esm5"
},
{
"binary_name": "unbound",
"binary_version": "1.5.8-1ubuntu1.1+esm5"
},
{
"binary_name": "unbound-anchor",
"binary_version": "1.5.8-1ubuntu1.1+esm5"
},
{
"binary_name": "unbound-host",
"binary_version": "1.5.8-1ubuntu1.1+esm5"
}
]
}
},
{
"ranges": [
{
"type": "ECOSYSTEM",
"events": [
{
"introduced": "0"
},
{
"fixed": "1.6.7-1ubuntu2.3"
}
]
}
],
"package": {
"name": "unbound",
"purl": "pkg:deb/ubuntu/unbound?arch=source&distro=bionic",
"ecosystem": "Ubuntu:18.04:LTS"
},
"versions": [
"1.6.5-1",
"1.6.7-1",
"1.6.7-1build1",
"1.6.7-1ubuntu1",
"1.6.7-1ubuntu2",
"1.6.7-1ubuntu2.1",
"1.6.7-1ubuntu2.2"
],
"database_specific": {
"source": "https://github.com/canonical/ubuntu-security-notices/blob/main/osv/cve/2020/UBUNTU-CVE-2020-12662.json"
},
"ecosystem_specific": {
"binaries": [
{
"binary_name": "libunbound2",
"binary_version": "1.6.7-1ubuntu2.3"
},
{
"binary_name": "python-unbound",
"binary_version": "1.6.7-1ubuntu2.3"
},
{
"binary_name": "python3-unbound",
"binary_version": "1.6.7-1ubuntu2.3"
},
{
"binary_name": "unbound",
"binary_version": "1.6.7-1ubuntu2.3"
},
{
"binary_name": "unbound-anchor",
"binary_version": "1.6.7-1ubuntu2.3"
},
{
"binary_name": "unbound-host",
"binary_version": "1.6.7-1ubuntu2.3"
}
],
"availability": "No subscription required"
}
},
{
"ranges": [
{
"type": "ECOSYSTEM",
"events": [
{
"introduced": "0"
},
{
"fixed": "1.9.4-2ubuntu1.1"
}
]
}
],
"package": {
"name": "unbound",
"purl": "pkg:deb/ubuntu/unbound?arch=source&distro=focal",
"ecosystem": "Ubuntu:20.04:LTS"
},
"versions": [
"1.9.0-2ubuntu1",
"1.9.0-2ubuntu2",
"1.9.4-2",
"1.9.4-2ubuntu1"
],
"database_specific": {
"source": "https://github.com/canonical/ubuntu-security-notices/blob/main/osv/cve/2020/UBUNTU-CVE-2020-12662.json"
},
"ecosystem_specific": {
"binaries": [
{
"binary_name": "libunbound8",
"binary_version": "1.9.4-2ubuntu1.1"
},
{
"binary_name": "python-unbound",
"binary_version": "1.9.4-2ubuntu1.1"
},
{
"binary_name": "python3-unbound",
"binary_version": "1.9.4-2ubuntu1.1"
},
{
"binary_name": "unbound",
"binary_version": "1.9.4-2ubuntu1.1"
},
{
"binary_name": "unbound-anchor",
"binary_version": "1.9.4-2ubuntu1.1"
},
{
"binary_name": "unbound-host",
"binary_version": "1.9.4-2ubuntu1.1"
}
],
"availability": "No subscription required"
}
}
],
"modified": "2026-10-21T16:30:10.638028139Z",
"provider": "osv",
"upstream": [
"CVE-2020-12662"
],
"references": [
"https://ubuntu.com/security/CVE-2020-12662",
"https://www.openwall.com/lists/oss-security/2020/05/19/5",
"https://ubuntu.com/security/notices/USN-4374-1",
"https://www.cve.org/CVERecord?id=CVE-2020-12662"
]
},
"related_cves": [
{
"value": "CVE-2020-12662",
"evidence": "/upstream"
}
],
"security_relevant": true,
"severity_evidence": "/severity/0/score"
},
"source_id": "core-osv",
"document_id": 394500,
"published_at": "2020-05-19T11:00:00+00:00"
}