CoreDNS transfer plugin subzone ACL bypass via lexicographic zone comparison
CoreDNS is a DNS server that chains plugins. In versions prior to 1.14.3, the transfer plugin can select the wrong ACL stanza when both a parent zone and a more-specific subzone are configured. The longestMatch() function in plugin/transfer/transfer.go uses a lexicographic string comparison instead of an actual longest-suffix match to select the winning zone. As a result, a permissive parent-zone transfer rule can override a restrictive subzone rule depending on zone name ordering (e.g., "example.org." > "a.example.org." lexicographically). This allows an unauthorized remote client to perform AXFR/IXFR for the subzone and retrieve its full zone contents. This issue has been fixed in version 1.14.3.
- Products
- Not specified
- Affected versions
- Not specified
- Fixed versions
- Not specified
- CVEs
- CVE-2026-33489
- Confirmed fixed CVEs
- Not specified
- Updated in this feed
- 6 Nov 2026, 02:16 UTC · Revision 1
Source evidence
CoreDNS transfer plugin subzone ACL bypass via lexicographic zone comparison
core-osv · Original sourcePublished 5 May 2026, 19:13 UTC
CoreDNS is a DNS server that chains plugins. In versions prior to 1.14.3, the transfer plugin can select the wrong ACL stanza when both a parent zone and a more-specific subzone are configured. The longestMatch() function in plugin/transfer/transfer.go uses a lexicographic string comparison instead of an actual longest-suffix match to select the winning zone. As a result, a permissive parent-zone transfer rule can override a restrictive subzone rule depending on zone name ordering (e.g., "example.org." > "a.example.org." lexicographically). This allows an unauthorized remote client to perform AXFR/IXFR for the subzone and retrieve its full zone contents. This issue has been fixed in version 1.14.3.
osv:CVE-2026-33489
Complete source record
{
"id": "b0f81fc3c99cac830cc8460d6152174d55dd1c8753899d2ce0b04116c9198857",
"url": "https://osv.dev/vulnerability/CVE-2026-33489",
"method": "structured",
"payload": {
"kind": "advisory",
"title": "CoreDNS transfer plugin subzone ACL bypass via lexicographic zone comparison",
"summary": "CoreDNS is a DNS server that chains plugins. In versions prior to 1.14.3, the transfer plugin can select the wrong ACL stanza when both a parent zone and a more-specific subzone are configured. The longestMatch() function in plugin/transfer/transfer.go uses a lexicographic string comparison instead of an actual longest-suffix match to select the winning zone. As a result, a permissive parent-zone transfer rule can override a restrictive subzone rule depending on zone name ordering (e.g., \"example.org.\" > \"a.example.org.\" lexicographically). This allows an unauthorized remote client to perform AXFR/IXFR for the subzone and retrieve its full zone contents. This issue has been fixed in version 1.14.3.",
"evidence": "osv:CVE-2026-33489",
"products": [],
"severity": "high",
"structured": {
"id": "CVE-2026-33489",
"aliases": [
"CVE-2026-33489",
"GHSA-h8mm-c463-wjq3",
"GO-2026-5417"
],
"metrics": [
{
"type": "CVSS_V4",
"score": "CVSS:4.0/AV:N/AC:L/AT:P/PR:N/UI:N/VC:H/VI:N/VA:N/SC:N/SI:N/SA:N"
}
],
"affected": [
{
"ranges": [
{
"repo": "https://github.com/coredns/coredns",
"type": "GIT",
"events": [
{
"introduced": "0"
},
{
"fixed": "17fceec6d93fd1dde5ba6888c363f131ff6d647f"
}
],
"database_specific": {
"extracted_events": [
{
"range": [
{
"introduced": "0"
},
{
"fixed": "1.14.3"
}
],
"source": "AFFECTED_FIELD",
"strategy": "StringRangeExpression"
},
{
"range": [
{
"fixed": "17fceec6d93fd1dde5ba6888c363f131ff6d647f"
}
],
"source": "REFERENCES_TAG",
"original_tag": "v1.14.3"
},
{
"cpe": "cpe:2.3:a:coredns.io:coredns:*:*:*:*:*:*:*:*",
"range": [
{
"introduced": "0"
},
{
"fixed": "1.14.3"
}
],
"source": "CPE_RANGE"
}
]
}
}
],
"versions": [
"v1.14.2",
"v1.14.1",
"v1.14.0",
"v1.13.2",
"v1.13.1",
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"v1.9.1",
"v1.9.0",
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"v1.8.6",
"v1.8.5",
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"v1.8.3",
"v1.8.2",
"v1.8.1",
"v1.8.0",
"v1.7.1",
"v1.7.0",
"v1.6.9",
"v1.6.8",
"v1.6.7",
"v1.6.6",
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"v1.6.1",
"v1.6.0",
"v1.5.2",
"v1.5.1",
"v1.5.0",
"v1.4.0",
"v1.3.1",
"v1.3.0",
"v1.2.6",
"v1.2.5",
"v1.2.4",
"v1.2.3",
"v1.2.2",
"v1.2.1",
"v1.2.0",
"v1.1.4",
"v1.1.3",
"v1.1.2",
"v1.1.1",
"v1.1.0",
"v1.0.6",
"v1.0.5",
"v1.0.3",
"v1.0.2",
"v1.0.1",
"v1.0.0",
"v0.9.10",
"v0.9.9",
"v011",
"v010",
"v009",
"v008",
"v007",
"v006",
"v005",
"v004",
"v003",
"v002",
"v001"
],
"database_specific": {
"source": "https://storage.googleapis.com/cve-osv-conversion/osv-output/CVE-2026-33489.json"
}
}
],
"modified": "2026-10-28T02:30:46.038512959Z",
"provider": "osv",
"references": [
"https://github.com/coredns/coredns/releases/tag/v1.14.3",
"https://github.com/CVEProject/cvelistV5/tree/main/cves/2026/33xxx/CVE-2026-33489.json",
"https://github.com/coredns/coredns/security/advisories/GHSA-h8mm-c463-wjq3",
"https://nvd.nist.gov/vuln/detail/CVE-2026-33489"
],
"provider_metadata": {
"cwe_ids": [
"CWE-863"
],
"cna_assigner": "GitHub_M",
"osv_generated_from": "https://github.com/CVEProject/cvelistV5/tree/main/cves/2026/33xxx/CVE-2026-33489.json"
}
},
"related_cves": [
{
"value": "CVE-2026-33489",
"evidence": "/id"
}
],
"security_relevant": true,
"severity_evidence": "/severity/0/score"
},
"source_id": "core-osv",
"document_id": 514202,
"published_at": "2026-05-05T19:13:48.461+00:00"
}