{"id":"CVE-2026-82399","title":"CoreDNS is a DNS server written in Go","summary":"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 d…","severity":"high","cvss":7.5,"cvssVector":"CVSS:3.1/AV:N/AC:L/PR:N/UI:N/S:U/C:N/I:N/A:H","cwe":["CWE-770","CWE-1050"],"vendor":"coredns","product":"coredns","affected":["coredns < 1.14.7"],"patched":["github.com/coredns/coredns 1.14.7"],"published":"2026-09-16","updated":"2026-09-18","sourceUpdated":"2026-09-18T19:16:46.077","source":"NVD","sourceUrl":"https://nvd.nist.gov/vuln/detail/CVE-2026-82399","references":[{"url":"https://github.com/coredns/coredns/commit/530b0a5ff2ad68cc0421f10dd93568945cc671c9","label":"security-advisories@github.com"},{"url":"https://github.com/coredns/coredns/releases/tag/v1.14.7","label":"security-advisories@github.com"},{"url":"https://github.com/coredns/coredns/security/advisories/GHSA-mrg3-qvqr-jw29","label":"security-advisories@github.com"},{"url":"https://github.com/coredns/coredns/security/advisories/GHSA-mrg3-qvqr-jw29","label":"134c704f-9b21-4f2e-91b3-4a467353bcc0"},{"url":"https://security.access.redhat.com/data/csaf/v2/vex/2026/cve-2026-82399.json"},{"url":"https://access.redhat.com/security/cve/CVE-2026-82399"},{"url":"https://bugzilla.redhat.com/show_bug.cgi?id=2535609"},{"url":"https://www.cve.org/CVERecord?id=CVE-2026-82399"},{"url":"https://nvd.nist.gov/vuln/detail/CVE-2026-82399"},{"url":"https://github.com/advisories/GHSA-mrg3-qvqr-jw29"},{"url":"https://github.com/coredns/coredns"}],"tags":["nvd","cve.org","csaf","vex","red-hat","ghsa","go","osv","exploit-available"],"epss":0.00609,"epssPercentile":0.47855,"aliases":["GHSA-mrg3-qvqr-jw29"],"ecosystem":"go","exploitAvailable":true,"ssvc":{"exploitation":"poc","automatable":"yes","technicalImpact":"partial","timestamp":"2026-09-18T18:18:56.250464Z"},"ingestedAt":"2026-09-16T19:02:30.728Z","slug":"CVE-2026-82399","body":"## Overview\n\nCoreDNS 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.\n\n## Remediation\n\nRefer to the linked advisories for vendor-supplied fixes and affected version ranges.\n\n## Package advisory (CVE-2026-82399)\n\nAffected packages:\n\n- `github.com/coredns/coredns <= 1.14.6`\n\nPatched in:\n\n- `github.com/coredns/coredns 1.14.7`\n\nSource: https://github.com/advisories/GHSA-mrg3-qvqr-jw29\n\n## Vendor advisories\n\n- **Red Hat VEX** · Important · affected: Red Hat Advanced Cluster Management for Kubernetes 2, Red Hat Connectivity Link 1, Red Hat OpenShift Container Platform 4 · no fix planned: Red Hat Advanced Cluster Management for Kubernetes 2, Red Hat Connectivity Link 1, Red Hat OpenShift Container Platform 4 · updated 2026-09-23 · [vex](https://security.access.redhat.com/data/csaf/v2/vex/2026/cve-2026-82399.json)","depth":"midnight","depthScore":53,"depthScoreParts":{"impact":41.3,"likelihood":0.1,"exploitation":12,"ransomware":0},"changes":[{"seq":207438,"id":"CVE-2026-82399","ts":1789757362618,"field":"exploit_available","old":"false","new":"true"}]}