9.1
Critical
CVE-2026-78663 The HTTP/2 server can refund connection-level flow control twice for the same data: Once when a client resets a stream…
Description
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.
Affected products and versions
| Product | Affected versions | Fixed in |
|---|---|---|
| net/http 1.26 | earliest → < 1.26.9 | 1.26.9 |
| net/http/internal/http2 1.27 | 1.27.0-0 → < 1.27.2 | 1.27.2 |
| golang.org/x/net/http2 0.60 | earliest → < 0.60.0 | 0.60.0 |
References
- go.dev go.dev
- go.dev go.dev
- go.dev go.dev
- groups.google.com groups.google.com
- groups.google.com groups.google.com
- pkg.go.dev pkg.go.dev
Timeline
- Published
- Last modified
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