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OpenAdvisories
High · 8.2 CVE-2026-33489 EUVD-2026-27450GHSA-h8mm-c463-wjq3GO-2026-5417

CoreDNS transfer plugin subzone ACL bypass via lexicographic zone comparison

Published May 5, 2026 · Updated May 5, 2026 · Assigned by GitHub_M

Description

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

VendorProductAffectedFixed
coredns coredns < 1.14.3 —

Fixed in Linux distributions

Distributions backport fixes, so the version that fixes this vulnerability differs per release — upgrade to at least the version shown. From the distributions' security trackers and advisories.

ReleasePackageFixed inAdvisory
openSUSE Leap 16.0 govulncheck-vulndb 0.0.20260723T184607-160000.1.1 openSUSE-SU-2026:21483-1

Azure Linux

ReleasePackageFixed inAdvisory
Azure Linux 3 coredns 1.11.4-17 —

Wolfi

ReleasePackageFixed inAdvisory
Wolfi rolling coredns-1.13 +1 No fix yet —
Wolfi rolling juicefs-1.3 1.3.1-r14 —
Wolfi rolling k8s_gateway 1.8.0-r1 —
Wolfi rolling kubernetes-dns-node-cache 1.26.8-r3 —

Affected packages

EcosystemPackageAffectedFixedRecord
Go github.com/coredns/coredns < 1.14.3 1.14.3 GHSA-h8mm-c463-wjq3

Advisories 2

References