netty: Fix client-initiated stream limit bypass in NettyServerHandler (v1.82.x backport) - #12941
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kannanjgithub merged 1 commit intoJul 29, 2026
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…grpc#12933) Configure connection.remote().maxActiveStreams(maxStreams) directly upon `DefaultHttp2Connection` initialization. Because `NettyServerHandler` instantiates `DefaultHttp2Connection` directly rather than using Netty's `AbstractHttp2ConnectionHandlerBuilder`, it missed Netty's built-in CVE-2026-47244 patch. This left a pre-handshake window where the server's local connection allowed up to Integer.MAX_VALUE active client-initiated streams until a SETTINGS_ACK was received. Enforcing the limit proactively at startup closes this vulnerability window and prevents client-initiated stream floods / resource exhaustion. Fixes grpc#12930
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Jul 29, 2026
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Backport of #12933 to v1.82.x.
Configure connection.remote().maxActiveStreams(maxStreams) directly upon
DefaultHttp2Connectioninitialization.Because
NettyServerHandlerinstantiatesDefaultHttp2Connectiondirectly rather than using Netty'sAbstractHttp2ConnectionHandlerBuilder, it missed Netty's built-in CVE-2026-47244 patch. This left a pre-handshake window where the server's local connection allowed up to Integer.MAX_VALUE active client-initiated streams until a SETTINGS_ACK was received. Enforcing the limit proactively at startup closes this vulnerability window and prevents client-initiated stream floods / resource exhaustion.Fixes #12930