CoreDNS is a DNS server written in Go. Prior to 1.14.7, the DNS-over-HTTPS, DNS-over-HTTP/3, DNS-over-QUIC, and DNS-over-gRPC listeners in plugin/pkg/doh/doh.go, core/dnsserver/server_quic.go, and core/dnsserver/server_grpc.go call dns.Msg.Unpack without the dns.DefaultMsgAcceptFunc request policy used by UDP, TCP, and DNS-over-TLS. An unauthenticated client can send an RFC 2136 UPDATE that the proxy or forward plugin passes unchanged to an update-capable upstream. If that upstream trusts CoreDNS's source address or connection and does not require an attacker-unknown end-to-end TSIG, the request appears to originate from CoreDNS and can add, replace, or delete DNS records, redirect traffic, take over names, alter mail routing, or disrupt the writable zone. This issue is fixed in version 1.14.7.
Metrics
Affected Vendors & Products
References
History
Sat, 19 Sep 2026 23:00:00 +0000
| Type | Values Removed | Values Added |
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| First Time appeared |
Coredns.io
Coredns.io coredns |
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| Vendors & Products |
Coredns.io
Coredns.io coredns |
Thu, 17 Sep 2026 20:30:00 +0000
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| Metrics |
ssvc
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Thu, 17 Sep 2026 12:15:00 +0000
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| Weaknesses | CWE-306 | |
| References |
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| Metrics |
threat_severity
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threat_severity
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Wed, 16 Sep 2026 19:00:00 +0000
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| Description | CoreDNS is a DNS server written in Go. Prior to 1.14.7, the DNS-over-HTTPS, DNS-over-HTTP/3, DNS-over-QUIC, and DNS-over-gRPC listeners in plugin/pkg/doh/doh.go, core/dnsserver/server_quic.go, and core/dnsserver/server_grpc.go call dns.Msg.Unpack without the dns.DefaultMsgAcceptFunc request policy used by UDP, TCP, and DNS-over-TLS. An unauthenticated client can send an RFC 2136 UPDATE that the proxy or forward plugin passes unchanged to an update-capable upstream. If that upstream trusts CoreDNS's source address or connection and does not require an attacker-unknown end-to-end TSIG, the request appears to originate from CoreDNS and can add, replace, or delete DNS records, redirect traffic, take over names, alter mail routing, or disrupt the writable zone. This issue is fixed in version 1.14.7. | |
| Title | CoreDNS DoH/DoQ/gRPC bypass UPDATE rejection enforced on UDP/TCP | |
| Weaknesses | CWE-441 | |
| References |
| |
| Metrics |
cvssV3_1
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Status: PUBLISHED
Assigner: GitHub_M
Published: 2026-09-16T18:39:22.955Z
Updated: 2026-09-17T19:25:42.634Z
Reserved: 2026-09-04T19:17:36.246Z
Link: CVE-2026-86003
Updated: 2026-09-17T17:06:23.818Z
Status : Awaiting Analysis
Published: 2026-09-16T19:17:51.760
Modified: 2026-09-24T21:24:11.250
Link: CVE-2026-86003