CVE-2026-33489

CoreDNS transfer plugin subzone ACL bypass via lexicographic zone comparison

HIGH
7.5
CVSS Score
Published: May 5, 2026 at 07:13 PM UTC
Updated: July 24, 2026 at 11:10 PM UTC
2 products affected across 1 vendorCorednsIo Coredns

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Severity
HIGH7.5
Exploit prediction
EPSS 0.4%
SSVC
PoC

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

Our own answer: ranges merged, affected separated from platform-only, with confidence and review flags.

v < 1.14.3
Affected range stops below 1.14.3, so it looks safe — our inference, not a vendor statement
v < 1.14.3
Affected range stops below 1.14.3, so it looks safe — our inference, not a vendor statement

Remediation

No guide yet

No remediation guidance has been written for this CVE yet. What the record does show:

References (2)

x_refsource_CONFIRMExploitVendor Advisory
Source: cverecord
https://github.com/coredns/coredns/security/advisories/GHSA-h8mm-c463-wjq3
x_refsource_MISCRelease Notes
Source: cverecord
https://github.com/coredns/coredns/releases/tag/v1.14.3

SSVC — Action Prioritization

SSVCPoCAutomatablePartial impact

SSVC signals action urgency (what to patch first), separate from CVSS which measures severity.

CVSS

Attack Vector
NETWORK
Complexity
LOW
Privileges
NONE
User Interaction
NONE
Scope
UNCHANGED
Confidentiality
HIGH
Integrity
NONE
Availability
NONE
Vector?

Quick Info

StatusANALYZED
CWE
CWE-863

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