{"id":"CVE-2026-32936","state":"PUBLISHED","title":"CoreDNS DoH GET path missing size validation causes CPU and memory amplification","description":"CoreDNS is a DNS server that chains plugins. In versions prior to 1.14.3, the DNS-over-HTTPS (DoH) GET path accepts oversized dns= query parameter values and performs URL query parsing, base64 decoding, and DNS message unpacking before rejecting the request. Unlike the POST path, which applies a bounded read via http.MaxBytesReader limited to 65536 bytes, the GET path has no equivalent size validation before expensive processing. A remote, unauthenticated attacker can repeatedly send oversized DoH GET requests to force high CPU usage, large transient memory allocations, and elevated garbage-collection pressure, leading to denial of service. This issue has been fixed in version 1.14.3.","publishedAt":"2026-05-05T19:07:51.926Z","updatedAt":"2026-05-05T19:32:25.341Z","severity":{"score":8.7,"label":"High","version":"4.0","vector":"CVSS:4.0/AV:N/AC:L/AT:N/PR:N/UI:N/VC:N/VI:N/VA:H/SC:N/SI:N/SA:N","source":"GitHub_M"},"assigner":"GitHub_M","products":["coredns coredns"],"affected":[{"vendor":"coredns","product":"coredns","versions":[{"version":"< 1.14.3","status":"affected"}]}],"references":["https://github.com/coredns/coredns/security/advisories/GHSA-63cw-r7xf-jmwr","https://github.com/coredns/coredns/releases/tag/v1.14.3"],"weaknesses":["CWE-400"],"ingestedAt":"2026-10-29T20:11:40.391Z","source":{"repository":"CVEProject/cvelistV5","path":"cves/2026/32xxx/CVE-2026-32936.json","commit":"556c9d3a8cd17e218bb8e452ba7cd619a384ff47"},"raw":{"dataType":"CVE_RECORD","dataVersion":"5.2","cveMetadata":{"cveId":"CVE-2026-32936","state":"PUBLISHED","datePublished":"2026-05-05T19:07:51.926Z","dateUpdated":"2026-05-05T19:32:25.341Z","assignerShortName":"GitHub_M","assignerOrgId":"a0819718-46f1-4df5-94e2-005712e83aaa","dateReserved":"2026-03-17T00:05:53.282Z"},"containers":{"cna":{"title":"CoreDNS DoH GET path missing size validation causes CPU and memory amplification","descriptions":[{"lang":"en","value":"CoreDNS is a DNS server that chains plugins. In versions prior to 1.14.3, the DNS-over-HTTPS (DoH) GET path accepts oversized dns= query parameter values and performs URL query parsing, base64 decoding, and DNS message unpacking before rejecting the request. Unlike the POST path, which applies a bounded read via http.MaxBytesReader limited to 65536 bytes, the GET path has no equivalent size validation before expensive processing. A remote, unauthenticated attacker can repeatedly send oversized DoH GET requests to force high CPU usage, large transient memory allocations, and elevated garbage-collection pressure, leading to denial of service. This issue has been fixed in version 1.14.3."}],"affected":[{"vendor":"coredns","product":"coredns","versions":[{"version":"< 1.14.3","status":"affected"}]}],"references":[{"url":"https://github.com/coredns/coredns/security/advisories/GHSA-63cw-r7xf-jmwr","name":"https://github.com/coredns/coredns/security/advisories/GHSA-63cw-r7xf-jmwr","tags":["x_refsource_CONFIRM"]},{"url":"https://github.com/coredns/coredns/releases/tag/v1.14.3","name":"https://github.com/coredns/coredns/releases/tag/v1.14.3","tags":["x_refsource_MISC"]}],"metrics":[{"cvssV4_0":{"attackVector":"NETWORK","attackComplexity":"LOW","attackRequirements":"NONE","privilegesRequired":"NONE","userInteraction":"NONE","vulnConfidentialityImpact":"NONE","vulnIntegrityImpact":"NONE","vulnAvailabilityImpact":"HIGH","subConfidentialityImpact":"NONE","subIntegrityImpact":"NONE","subAvailabilityImpact":"NONE","baseScore":8.7,"baseSeverity":"HIGH","vectorString":"CVSS:4.0/AV:N/AC:L/AT:N/PR:N/UI:N/VC:N/VI:N/VA:H/SC:N/SI:N/SA:N","version":"4.0"}}],"problemTypes":[{"descriptions":[{"cweId":"CWE-400","lang":"en","description":"CWE-400: Uncontrolled Resource Consumption","type":"CWE"}]}],"providerMetadata":{"shortName":"GitHub_M","orgId":"a0819718-46f1-4df5-94e2-005712e83aaa","dateUpdated":"2026-05-05T19:07:51.926Z"},"source":{"advisory":"GHSA-63cw-r7xf-jmwr","discovery":"UNKNOWN"}},"adp":[{"title":"CISA ADP Vulnrichment","references":[{"url":"https://github.com/coredns/coredns/security/advisories/GHSA-63cw-r7xf-jmwr","tags":["exploit"]}],"metrics":[{"other":{"type":"ssvc","content":{"timestamp":"2026-05-05T19:32:21.653054Z","id":"CVE-2026-32936","options":[{"Exploitation":"poc"},{"Automatable":"yes"},{"Technical Impact":"partial"}],"role":"CISA Coordinator","version":"2.0.3"}}}],"providerMetadata":{"shortName":"CISA-ADP","orgId":"134c704f-9b21-4f2e-91b3-4a467353bcc0","dateUpdated":"2026-05-05T19:32:25.341Z"}}]}}}