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 request paths in plugin/pkg/doh/doh.go, core/dnsserver/server_quic.go, and core/dnsserver/server_grpc.go call dns.Msg.Unpack on attacker-controlled DNS section counts before dns.DefaultMsgAcceptFunc validates the fixed header. An unauthenticated client can use DNS name compression and excessive section counts to amplify allocation before the plugin chain, so plugin-level rate limiting cannot prevent concurrent requests from exhausting memory and terminating CoreDNS. The ordinary UDP and TCP listeners are not affected because they validate the header first. This issue is fixed in version 1.14.7.
Advisories
Source ID Title
Github GHSA Github GHSA GHSA-mrg3-qvqr-jw29 CoreDNS: Unauthenticated memory exhaustion in custom transports
Fixes

Solution

No solution given by the vendor.


Workaround

No workaround given by the vendor.

History

Fri, 18 Sep 2026 23:45:00 +0000

Type Values Removed Values Added
First Time appeared Coredns.io
Coredns.io coredns
Vendors & Products Coredns.io
Coredns.io coredns

Fri, 18 Sep 2026 21:30:00 +0000

Type Values Removed Values Added
Metrics ssvc

{'options': {'Automatable': 'yes', 'Exploitation': 'poc', 'Technical Impact': 'partial'}, 'version': '2.0.3'}


Thu, 17 Sep 2026 12:15:00 +0000

Type Values Removed Values Added
Weaknesses CWE-1050
References
Metrics threat_severity

None

threat_severity

Important


Wed, 16 Sep 2026 19:00:00 +0000

Type Values Removed Values Added
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 request paths in plugin/pkg/doh/doh.go, core/dnsserver/server_quic.go, and core/dnsserver/server_grpc.go call dns.Msg.Unpack on attacker-controlled DNS section counts before dns.DefaultMsgAcceptFunc validates the fixed header. An unauthenticated client can use DNS name compression and excessive section counts to amplify allocation before the plugin chain, so plugin-level rate limiting cannot prevent concurrent requests from exhausting memory and terminating CoreDNS. The ordinary UDP and TCP listeners are not affected because they validate the header first. This issue is fixed in version 1.14.7.
Title CoreDNS: Unauthenticated memory exhaustion in custom transports
Weaknesses CWE-770
References
Metrics cvssV3_1

{'score': 7.5, 'vector': 'CVSS:3.1/AV:N/AC:L/PR:N/UI:N/S:U/C:N/I:N/A:H'}


Projects

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cve-icon MITRE

Status: PUBLISHED

Assigner: GitHub_M

Published:

Updated: 2026-09-18T18:19:57.712Z

Reserved: 2026-08-28T22:00:43.512Z

Link: CVE-2026-82399

cve-icon Vulnrichment

Updated: 2026-09-18T18:19:36.657Z

cve-icon NVD

Status : Received

Published: 2026-09-16T19:17:44.627

Modified: 2026-09-18T19:16:46.077

Link: CVE-2026-82399

cve-icon Redhat

Severity : Important

Publid Date: 2026-09-16T18:37:55Z

Links: CVE-2026-82399 - Bugzilla

cve-icon OpenCVE Enrichment

Updated: 2026-09-18T21:45:14Z

Weaknesses