CoreDNS is a DNS server that chains plugins. In versions prior to 1.14.3, the tsig plugin can be bypassed on non-plain-DNS transports (DoT, DoH, DoH3, DoQ, and gRPC) because it trusts the transport writer's TsigStatus() instead of performing verification itself. The DoH and DoH3 writer's TsigStatus() always returns nil, the DoT server does not set TsigSecret on the dns.Server, and the DoQ and gRPC writers also unconditionally return nil. This allows an unauthenticated remote client to bypass TSIG-based authentication and access resources intended to be restricted behind a tsig require all policy. Plain DNS over TCP and UDP are not affected. This issue has been fixed in version 1.14.3.
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Affected Vendors & Products
References
History
Wed, 06 May 2026 13:15:00 +0000
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ssvc
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Tue, 05 May 2026 21:45:00 +0000
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Coredns.io
Coredns.io coredns |
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Coredns.io
Coredns.io coredns |
Tue, 05 May 2026 19:30:00 +0000
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| Description | CoreDNS is a DNS server that chains plugins. In versions prior to 1.14.3, the tsig plugin can be bypassed on non-plain-DNS transports (DoT, DoH, DoH3, DoQ, and gRPC) because it trusts the transport writer's TsigStatus() instead of performing verification itself. The DoH and DoH3 writer's TsigStatus() always returns nil, the DoT server does not set TsigSecret on the dns.Server, and the DoQ and gRPC writers also unconditionally return nil. This allows an unauthenticated remote client to bypass TSIG-based authentication and access resources intended to be restricted behind a tsig require all policy. Plain DNS over TCP and UDP are not affected. This issue has been fixed in version 1.14.3. | |
| Title | CoreDNS TSIG authentication bypass on encrypted DNS transports | |
| Weaknesses | CWE-303 | |
| References |
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| Metrics |
cvssV4_0
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Status: PUBLISHED
Assigner: GitHub_M
Published: 2026-05-05T19:02:55.374Z
Updated: 2026-05-06T12:47:07.338Z
Reserved: 2026-03-17T22:16:36.721Z
Link: CVE-2026-33190
Updated: 2026-05-06T12:47:04.599Z
Status : Awaiting Analysis
Published: 2026-05-05T20:16:36.167
Modified: 2026-05-07T15:06:40.750
Link: CVE-2026-33190
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