{"id":"CVE-2026-78659","revision":"d331c684624446df98353b944ff91152","records":[{"revision":"d331c684624446df98353b944ff91152","observedAt":"2026-10-25T16:19:04.694+00:00","statement":{"source":"nvd","id":"CVE-2026-78659","aliases":[],"title":"When \"Trailer\" headers are sent by a client, the HTTP server internally uses the header values to populate the Request.Trailer map passed to the server handler. Because Request.Trailer is a map, each entry incurs memory overhead. For HTTP/2…","description":"When \"Trailer\" headers are sent by a client, the HTTP server internally uses the header values to populate the Request.Trailer map passed to the server handler. Because Request.Trailer is a map, each entry incurs memory overhead. For HTTP/2 servers, a malicious client can exploit this by sending a \"Trailer\" header that declares a large number of fields, causing the server to allocate a disproportionate amount of memory while bypassing Server.MaxHeaderValueCount and Server.MaxHeaderBytes limits. This exploit is not applicable for HTTP/1 servers, which do not support multiplexing a large number of requests over one TCP connection, and whose Server.MaxHeaderBytes are calculated differently.","state":0,"publishedAt":"2026-10-08T23:17:03.27+00:00","modifiedAt":"2026-10-09T16:35:35.9+00:00","affected":[],"metrics":[{"system":"CVSS 3.1 · 134c704f-9b21-4f2e-91b3-4a467353bcc0 · Secondary","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://go.dev/cl/847185","https://go.dev/cl/847314","https://go.dev/issue/81857","https://groups.google.com/g/golang-announce/c/U2fTuyDJznI","https://groups.google.com/g/golang-announce/c/ZPwCyRUuGBs","https://pkg.go.dev/vuln/GO-2026-6603"],"sourceUrl":"https://nvd.nist.gov/vuln/detail/CVE-2026-78659","license":"NIST NVD usage terms; underlying source attribution retained","enrichment":{"sourceStatus":"Awaiting Analysis","weaknesses":["CWE-405"],"productCriteria":[],"sourceDates":{"published":"2026-10-08T23:17:03.270","lastModified":"2026-10-09T16:35:35.900"},"relatedAdvisories":[],"note":"NVD analysis and CPE criteria are source context, not proof that a package or your environment is affected. Complete affected data, logical configurations and SSVC are retained in the original JSON."},"key":"nvd:CVE-2026-78659","identifiers":["CVE-2026-78659"]},"retained":false,"historicalAffected":[]}],"coverage":[]}