CVE-2026-33489
CoreDNS' transfer stanza selection uses lexicographic compare (subzone ACL bypass)
Impact
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.
Affected packages
| Ecosystem | Package | Affected | Fixed in |
|---|---|---|---|
| go | github.com/coredns/coredns | < 1.14.3 | 1.14.3 |
Affected products
| Vendor | Product | Affected versions |
|---|---|---|
| Coredns.Io | Coredns | before 1.14.3 |