CVE-2026-33489: Coredns.io Coredns

High severity, CVSS 7.5. EPSS: 0.4% chance of exploitation in the next 30 days.

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 products

• Coredns.io Coredns: before 1.14.3 (fixed in 1.14.3)

Published 2026-05-05. Last modified 2026-07-24.