{"id":"CVE-2026-73550","revision":null,"records":[{"revision":"4c9e532625b849ba99427e6159bffe68","observedAt":"2026-10-23T15:48:27.903+00:00","statement":{"source":"cve-program","id":"CVE-2026-73550","aliases":[],"title":"Envoy: HTTP/2 Discarded Host Header 200 GB Header-Copy OOM in Envoy","description":"Envoy is an open source edge and service proxy designed for cloud-native applications. Prior to 1.36.10, 1.37.6, 1.38.4, and 1.39.1, Envoy copies every decoded HTTP/2 Host header value before discarding it when :authority is already present. The discarded value bypasses saveHeader, so its bytes and count are not charged against request header limits. An unauthenticated client can use HPACK indexing to submit many references to a large Host value across a bounded number of streams, forcing extreme header-copy allocation and causing the proxy to be out-of-memory killed. The relevant scope boundary is that the demonstrated amplification uses HTTP/2 HPACK and the duplicate Host discard behavior. This issue is fixed in versions 1.36.10, 1.37.6, 1.38.4, and 1.39.1.","state":0,"publishedAt":"2026-09-21T19:49:28.641+00:00","modifiedAt":"2026-09-28T20:37:02.865+00:00","affected":[{"ecosystem":"Vendor product","name":"envoy","ranges":[],"versions":[],"rawVersionEvidence":"{\n                    \"vendor\": \"envoyproxy\",\n                    \"product\": \"envoy\",\n                    \"versions\": [\n                        {\n                            \"version\": \"< 1.36.10\",\n                            \"status\": \"affected\"\n                        },\n                        {\n                            \"version\": \">= 1.37.0, < 1.37.6\",\n                            \"status\": \"affected\"\n                        },\n                        {\n                            \"version\": \">= 1.38.0, < 1.38.4\",\n                            \"status\": \"affected\"\n                        },\n                        {\n                            \"version\": \">= 1.39.0, < 1.39.1\",\n                            \"status\": \"affected\"\n                        }\n                    ]\n                }"}],"metrics":[{"system":"CVSS 3.1","vector":"CVSS:3.1/AV:N/AC:L/PR:N/UI:N/S:U/C:N/I:N/A:H","score":7.5,"severity":"HIGH"}],"references":["https://github.com/envoyproxy/envoy/security/advisories/GHSA-qgf6-qvhw-4hvh","https://github.com/envoyproxy/envoy/commit/0910997f70e91d2d20c329bb507bfce44ce01f80","https://github.com/envoyproxy/envoy/commit/1fec994c868df008cdd4ae285aab58a196fd31f2","https://github.com/envoyproxy/envoy/commit/3fd0ffee7ac87adf3bc6e421656bb96310512300","https://github.com/envoyproxy/envoy/commit/fc75d8e35b0d11acbae18b63a0bd96e32e84f61b","https://github.com/envoyproxy/envoy/releases/tag/v1.36.10","https://github.com/envoyproxy/envoy/releases/tag/v1.37.6","https://github.com/envoyproxy/envoy/releases/tag/v1.38.4","https://github.com/envoyproxy/envoy/releases/tag/v1.39.1"],"sourceUrl":"https://www.cve.org/CVERecord?id=CVE-2026-73550","license":"CVE Program Terms of Use","key":"cve-program:CVE-2026-73550","identifiers":["CVE-2026-73550"]},"retained":false,"historicalAffected":[]}],"coverage":[{"source":"cisa-kev:global","scope":"Complete CISA KEV catalog; all vendors. Missing entries do not establish absence of exploitation.","generation":"2026-11-12T07:54:58.2349119+00:00","complete":true,"records":1779,"lastAttemptAt":"2026-11-12T07:54:58.2349119+00:00","lastSuccessAt":"2026-11-12T07:54:58.4848198+00:00","error":null,"lastVerifiedAt":"2026-11-12T07:54:58.4848225+00:00","snapshotPublishedAt":null,"importing":false,"stagedRecords":0,"checkedIdentifiers":null,"expectedIdentifiers":null,"failedIdentifiers":null},{"source":"cve-program","scope":"Official CVE Program baseline and cumulative hourly delta; all vendors, published and rejected records","generation":"cve-64752486c567b55b31fb0d7225f5222bcd0019564ac0ac5f0649e242c7b19299-1225a640a70b576ed1a85d2671a302d70a8e18168f570c1f4912faf8f66b1119","complete":true,"records":424623,"lastAttemptAt":"2026-11-12T07:53:22.876714+00:00","lastSuccessAt":"2026-11-12T07:53:22.8444514+00:00","error":null,"lastVerifiedAt":"2026-11-12T07:53:22.876714+00:00","snapshotPublishedAt":"2026-11-12T07:24:53+00:00","importing":false,"stagedRecords":0,"checkedIdentifiers":null,"expectedIdentifiers":null,"failedIdentifiers":null},{"source":"euvd","scope":"Rolling EUVD lookups of CVE aliases in current public OSV archives; 500 identifiers per refresh, rechecked after 48 hours. Not a global EUVD catalog. Successful not-found lookups count as checked; they do not imply withdrawal or safety. No reader inventory is sent.","generation":"enrichment-570328139368428ca550af1570d01579","complete":true,"records":13760,"lastAttemptAt":"2026-11-12T07:55:38.9446123+00:00","lastSuccessAt":"2026-11-12T06:55:06.923+00:00","error":null,"lastVerifiedAt":"2026-11-12T06:55:06.923+00:00","snapshotPublishedAt":null,"importing":false,"stagedRecords":0,"checkedIdentifiers":13813,"expectedIdentifiers":13813,"failedIdentifiers":0},{"source":"first-epss:nuget","scope":"FIRST EPSS for explicit CVE aliases in the collected public NuGet archive. Not a global EPSS backfill.","generation":"2026-11-12T07:54:58.2349119+00:00","complete":true,"records":1097,"lastAttemptAt":"2026-11-12T07:54:58.2349119+00:00","lastSuccessAt":"2026-11-12T07:54:58.4862124+00:00","error":null,"lastVerifiedAt":"2026-11-12T07:54:58.4862143+00:00","snapshotPublishedAt":null,"importing":false,"stagedRecords":0,"checkedIdentifiers":null,"expectedIdentifiers":null,"failedIdentifiers":null},{"source":"nvd","scope":"Rolling NVD lookups of CVE aliases in current public OSV archives; 500 identifiers per refresh, rechecked after 48 hours. Not a global NVD catalog. Successful not-found lookups count as checked; they do not imply withdrawal or safety. No reader inventory is sent.","generation":"enrichment-8017f5c1a44c430b920cd4f30d507e78","complete":true,"records":13760,"lastAttemptAt":"2026-11-12T07:55:38.3687422+00:00","lastSuccessAt":"2026-11-12T07:55:38.365+00:00","error":null,"lastVerifiedAt":"2026-11-12T07:55:38.365+00:00","snapshotPublishedAt":null,"importing":false,"stagedRecords":0,"checkedIdentifiers":13813,"expectedIdentifiers":13813,"failedIdentifiers":0},{"source":"osv:Go","scope":"Complete OSV Go ecosystem archive, including withdrawn and malicious-package source records; statement counts are not unique CVE counts","generation":"go-3562b6c78fd1bd0f0b55daf66a0926ae24f65e462df7f6d928caad458fc696bf","complete":true,"records":9947,"lastAttemptAt":"2026-11-12T07:54:58.021445+00:00","lastSuccessAt":"2026-11-11T04:27:43.6877707+00:00","error":null,"lastVerifiedAt":"2026-11-12T07:54:58.021445+00:00","snapshotPublishedAt":"2026-11-11T03:32:46+00:00","importing":false,"stagedRecords":0,"checkedIdentifiers":null,"expectedIdentifiers":null,"failedIdentifiers":null},{"source":"osv:NuGet","scope":"Complete OSV NuGet ecosystem archive, including GitHub Advisory Database records; NuGet version matching only","generation":"nuget-456002455e0ab94bb92c95476d4e6d175c104cd594749982afd96c893728ecbc","complete":true,"records":2010,"lastAttemptAt":"2026-11-12T07:53:23.1198989+00:00","lastSuccessAt":"2026-11-11T02:36:58.1276999+00:00","error":null,"lastVerifiedAt":"2026-11-12T07:53:23.1198989+00:00","snapshotPublishedAt":"2026-11-11T01:17:51+00:00","importing":false,"stagedRecords":0,"checkedIdentifiers":null,"expectedIdentifiers":null,"failedIdentifiers":null},{"source":"osv:crates.io","scope":"Complete OSV crates.io ecosystem archive, including withdrawn and malicious-package source records; statement counts are not unique CVE counts","generation":"crates.io-baa8362b4daf9e5f39d5563775a55935e7b442c0735d33274a921579ce4a0d66","complete":true,"records":3093,"lastAttemptAt":"2026-11-12T07:54:58.1995224+00:00","lastSuccessAt":"2026-11-11T13:00:02.5446881+00:00","error":null,"lastVerifiedAt":"2026-11-12T07:54:58.1995224+00:00","snapshotPublishedAt":"2026-11-11T12:47:47+00:00","importing":false,"stagedRecords":0,"checkedIdentifiers":null,"expectedIdentifiers":null,"failedIdentifiers":null},{"source":"osv:npm","scope":"Complete OSV npm ecosystem archive, including withdrawn and malicious-package source records; statement counts are not unique CVE counts","generation":"npm-3c15e3b4b3da393566ac7be69c095bef52c252ec437d24c4c6ea68ed9e4af0f5","complete":true,"records":231700,"lastAttemptAt":"2026-11-12T07:54:57.8931777+00:00","lastSuccessAt":"2026-11-12T07:54:56.4668314+00:00","error":null,"lastVerifiedAt":"2026-11-12T07:54:57.8931777+00:00","snapshotPublishedAt":"2026-11-12T07:33:19+00:00","importing":false,"stagedRecords":0,"checkedIdentifiers":null,"expectedIdentifiers":null,"failedIdentifiers":null}]}