CVE-2026-78663
criticalThe 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…
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.
CVSS:3.1/AV:N/AC:L/PR:N/UI:N/S:U/C:N/I:H/A:H Affected products
Not reported by the source (unknown — not "none").
Weakness classification (CWE)
Source: NVD / CISA. “NVD-CWE-Other” and “NVD-CWE-noinfo” mean NVD could not assign a specific weakness.
Mitigation & advisories
No vendor advisory or patch reference tagged by NVD. Check the references below.
References
- https://go.dev/cl/847187 security@golang.org
- https://go.dev/cl/847310 security@golang.org
- https://go.dev/issue/81743 security@golang.org
- https://groups.google.com/g/golang-announce/c/U2fTuyDJznI security@golang.org
- https://groups.google.com/g/golang-announce/c/ZPwCyRUuGBs security@golang.org
- https://pkg.go.dev/vuln/GO-2026-6612 security@golang.org