{"id":"BIT-golang-2026-78663","summary":"Double flow control refund on HTTP/2 server streams in net/http","details":"The HTTP/2 server can refund connection-level flow control twice for the same data: Once when a client resets a stream (refunding data for any sent-but-unread portion of the stream), and again when a request handler reads the buffered data. A malicious client can exploit this to bypass the configured connection-level flow control limit (MaxReceiveBufferPerConnection). Total buffered data is still limited by the concurrent stream limit and stream-level flow control.","aliases":["CVE-2026-78663","GO-2026-6612"],"modified":"2026-10-16T09:55:54.129082194Z","published":"2026-10-16T08:40:03.193Z","database_specific":{"severity":"Critical","cpes":["cpe:2.3:a:golang:go:*:*:*:*:*:*:*:*"]},"references":[{"type":"WEB","url":"https://go.dev/cl/847187"},{"type":"WEB","url":"https://go.dev/cl/847310"},{"type":"WEB","url":"https://go.dev/issue/81743"},{"type":"WEB","url":"https://groups.google.com/g/golang-announce/c/U2fTuyDJznI"},{"type":"WEB","url":"https://groups.google.com/g/golang-announce/c/ZPwCyRUuGBs"},{"type":"WEB","url":"https://nvd.nist.gov/vuln/detail/CVE-2026-78663"},{"type":"WEB","url":"https://pkg.go.dev/vuln/GO-2026-6612"}],"affected":[{"package":{"name":"golang","ecosystem":"Bitnami","purl":"pkg:bitnami/golang"},"ranges":[{"type":"SEMVER","events":[{"introduced":"0"},{"fixed":"1.26.9"},{"introduced":"1.27.0-0"},{"fixed":"1.27.2"}]}],"database_specific":{"source":"https://github.com/bitnami/vulndb/tree/main/data/golang/BIT-golang-2026-78663.json"},"severity":[{"type":"CVSS_V3","score":"CVSS:3.1/AV:N/AC:L/PR:N/UI:N/S:U/C:N/I:H/A:H"}]}],"schema_version":"1.9.0"}