{"id":"CVE-2026-32936","title":"github.com/coredns/coredns: CoreDNS: Denial of Service via oversized DNS-over-HTTPS GET requests (CVE-2026-32936)","summary":"A flaw was found in CoreDNS, a DNS server that chains plugins. A remote, unauthenticated attacker can exploit this vulnerability by repeatedly sending oversized DNS-over-HTTPS (DoH) GET requests. The GET path, unlike the POST path, lacks s…","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","cvssSource":"vendor","cwe":"CWE-1284","vendor":"Red Hat","product":"Red Hat Advanced Cluster Management for Kubernetes 2.14","affected":["advanced_cluster_management_for_kubernetes 2.14"],"patched":["advanced_cluster_management_for_kubernetes 2.14"],"published":"2026-05-05","updated":"2026-10-16","sourceUpdated":"2026-10-16T23:22:28+00:00","source":"CSAF","sourceUrl":"https://security.access.redhat.com/data/csaf/v2/vex/2026/cve-2026-32936.json","references":[{"url":"https://security.access.redhat.com/data/csaf/v2/vex/2026/cve-2026-32936.json"},{"url":"https://access.redhat.com/security/cve/CVE-2026-32936"},{"url":"https://bugzilla.redhat.com/show_bug.cgi?id=2466869"},{"url":"https://www.cve.org/CVERecord?id=CVE-2026-32936"},{"url":"https://nvd.nist.gov/vuln/detail/CVE-2026-32936"},{"url":"https://github.com/coredns/coredns/releases/tag/v1.14.3"},{"url":"https://github.com/coredns/coredns/security/advisories/GHSA-63cw-r7xf-jmwr"},{"url":"https://access.redhat.com/errata/RHSA-2026:25127"},{"url":"https://github.com/coredns/coredns"}],"tags":["csaf","vex","red-hat","osv","go"],"epss":0.00672,"epssPercentile":0.51864,"aliases":["GHSA-63cw-r7xf-jmwr","GO-2026-5164"],"ecosystem":"go","ingestedAt":"2026-09-12T03:13:01.757Z","slug":"CVE-2026-32936","body":"## Overview\n\nA flaw was found in CoreDNS, a DNS server that chains plugins. A remote, unauthenticated attacker can exploit this vulnerability by repeatedly sending oversized DNS-over-HTTPS (DoH) GET requests. The GET path, unlike the POST path, lacks size validation before processing large `dns=` query parameter values. This can lead to high CPU usage, significant memory allocations, and increased garbage collection, resulting in a Denial of Service (DoS).\n\n## Vendor advisories\n\n- **RHSA-2026:25127** · Red Hat · fixed in: Red Hat Advanced Cluster Management for Kubernetes 2.14 · released 2026-06-10 · [advisory](https://access.redhat.com/errata/RHSA-2026:25127)\n\n**github.com/coredns/coredns: CoreDNS: Denial of Service via oversized DNS-over-HTTPS GET requests** — rated Moderate by Red Hat. Released 2026-05-05, updated 2026-10-16.\n\nFixed:\n\n- Red Hat Advanced Cluster Management for Kubernetes 2.14\n\nNot affected:\n\n- Red Hat Advanced Cluster Management for Kubernetes 2.14\n- Red Hat OpenShift Container Platform 4\n\n## Remediation\n\nFor release note details, see the upstream Submariner release notes:\n\nhttps://submariner.io/community/releases/\n\nDownstream-specific issues resolved:\n* ACM-27238\n* ACM-28294\n* ACM-28295\n* ACM-28311\n* ACM-28313\n* ACM-28314\n* ACM-28315\n* ACM-28316\n* ACM-28329\n* ACM-28331\n* ACM-28333\n* ACM-28335\n* ACM-28337\n* ACM-28339\n* ACM-28342\n* ACM-29317\n* ACM-29511\n* ACM-29613\n* ACM-29614\n* ACM-29631\n* ACM-29632\n* ACM-29633\n* ACM-29634\n* ACM-29776\n* ACM-30134\n* ACM-30726\n* ACM-30727\n* ACM-30728\n* ACM-30729\n* ACM-30970\n* ACM-31136\n* ACM-31831\n* ACM-31840\n* ACM-32575\n* ACM-32842\n* ACM-34108\n* ACM-34586\n* ACM… https://access.redhat.com/errata/RHSA-2026:25127\n\nWorkarounds / mitigations:\n\n- Mitigation for this issue is either not available or the currently available options do not meet the Red Hat Product Security criteria comprising ease of use and deployment, applicability to widespread installation base, or stability.\n\n## Package advisory (CVE-2026-32936)\n\nAffected packages:\n\n- `github.com/coredns/coredns < 1.14.3`\n\nPatched in:\n\n- `github.com/coredns/coredns 1.14.3`\n\nSource: https://osv.dev/vulnerability/GHSA-63cw-r7xf-jmwr","depth":"twilight","depthScore":41,"depthScoreParts":{"impact":41.3,"likelihood":0.1,"exploitation":0,"ransomware":0},"changes":[]}