netty: Fix client-initiated stream limit bypass in NettyServerHandler (v1.83.x backport) - #12942
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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
shivaspeaks
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Jul 29, 2026
halibobo1205
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1. bump grpcVersion to 1.83.1 to pick up the upstream fix for grpc/grpc-java#12930 (PR grpc/grpc-java#12942), which enforces connection.remote().maxActiveStreams(maxStreams) at handler startup 2. drop GrpcNettyMaxConcurrentStreamsLimiter, the local protocol-negotiator shim that applied the same limit while 1.83.0 left the remote endpoint unbounded until the client acknowledged SETTINGS
halibobo1205
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1. bump grpcVersion to 1.83.1 to pick up the upstream fix for grpc/grpc-java#12930 (PR grpc/grpc-java#12942), which enforces connection.remote().maxActiveStreams(maxStreams) at handler startup 2. drop GrpcNettyMaxConcurrentStreamsLimiter, the local protocol-negotiator shim that applied the same limit while 1.83.0 left the remote endpoint unbounded until the client acknowledged SETTINGS
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Backport of #12933 to v1.83.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