Release 1.83.1

Security

• xds/rbac: Fix a bug where nested Principal or Permission rules with :scheme or grpc- prefixed header matchers were not rejected, which could cause DENY rules to fail open. (#9258)
  • Special Thanks: @nvxbug
• xds/rbac: Fix a bug where the host header matcher was not being replaced with :authority in nested Principal or Permission rules. (#9258)
  • Special Thanks: @nvxbug
• xds/rbac: Fix a bug where a header matcher whose name was not lowercase, such as X-Role, matched no header, which could cause DENY rules to fail open. (#9332)
  • Special Thanks: @alimony
• xds/rbac: Fix a bug where a :scheme or grpc- prefixed header matcher was accepted when its name was not lowercase. (#9332)
  • Special Thanks: @alimony
• xds/rbac: Fix a bug where a Host header matcher was not replaced with :authority. (#9332)
  • Special Thanks: @alimony

Performance

• transport: Restrict memory overhead of buffering small data frames. (#9331)

Release 1.83.0

Security

• server: Stop reading from connections when flooded by HTTP/2 frames to mitigate resource exhaustion. The default value for this limit is 100 frames, excluding DATA and HEADERS, and may be changed by setting environment variable GRPC_GO_EXPERIMENTAL_CONTROL_BUFFER_THROTTLE_LIMIT.
• xds/rbac: Support Metadata and RequestedServerName permissions matcher fields. If present in a DENY rule, previously these would be ignored and fail-open.
• xds/rbac: Fix panic when parsing unsupported fields in NotRule/NotId permissions.
• xds/rbac: Support the deprecated source_ip principal identifier by treating it as equivalent to direct_remote_ip.
• xds: Fix panic when parsing route header matchers configured with empty exact_match, prefix_match, or suffix_match strings. (#9223)

New Features

• xds/googlec2p: Enable DirectPath over Interconnect support for on-premises clients via the force-xds target URI query parameter. (#9133)
• xds: Enable xDS configuration to control which fields get propagated from ORCA backend metric reports to LRS load reports. (#9145)
• authz: Add OnPolicyUpdate callback to FileWatcherOptions to notify when an authz policy is loaded or updated. (#9142)
  • Special Thanks: @hnefatl
• xds: Add support for the GCP Authentication HTTP Filter, which automatically fetches and attaches GCP Service Account Identity JWT tokens to outgoing RPCs.
  • This feature can be enabled by setting environment variable GRPC_EXPERIMENTAL_XDS_GCP_AUTHENTICATION_FILTER=true. (#9119)
• xds: Add support for xDS-based HTTP CONNECT proxies.
  • This feature can be enabled by setting environment variable GRPC_EXPERIMENTAL_XDS_HTTP_CONNECT=true. (#9151)
• xds: Add support for contains_match in route header matchers. (#9223)

Bug Fixes

• credentials/alts: Fix panic when processing malformed frames by validating that the message frame length exceeds the message type field size. (#9197)
• grpc: Fix compilation on Plan 9 targets (GOOS=plan9), broken since v1.81.0. (#9255)
  • Special Thanks: @Yusufihsangorgel

Release 1.82.1

Security

• server: Stop reading from the connection when flooded by HTTP/2 frames. The default value for this limit is 100 frames, excluding DATA and HEADERS, and may be changed by setting environment variable GRPC_GO_EXPERIMENTAL_CONTROL_BUFFER_THROTTLE_LIMIT.
• xds/rbac: Support Metadata and RequestedServerName permissions matcher fields. If present in a DENY rule, previously these would be ignored and fail-open.
• xds/rbac: Fix panic when parsing unsupported fields in NotRule/NotId permissions.
• xds/rbac: Support the deprecated source_ip principal identifier by treating it as equivalent to direct_remote_ip.

Release 1.82.0

Behavior Changes

• server: Remove support for GRPC_GO_EXPERIMENTAL_DISABLE_STRICT_PATH_CHECKING environment varibale. Strict incoming RPC path validation (which has been the default since v1.79.3) can no longer be disabled. (#9112)
• transport: Add environment variable to change the default max header list size from 16MB to 8KB. This may be enabled by setting GRPC_GO_EXPERIMENTAL_ENABLE_8KB_DEFAULT_HEADER_LIST_SIZE=true. This will be enabled by default in a subsequent release. (#9019)
• balancer: Load Balancing policy registry is now case-sensitive. Set GRPC_GO_EXPERIMENTAL_CASE_SENSITIVE_BALANCER_REGISTRIES=false (and file an issue) to revert to case-insensitive behavior. (#9017)

New Features

• experimental/stats: Expose a new API, NewContextWithLabelCallback, to register a callback that is invoked when telemetry labels are added. (#8877)
  • Special Thanks: @seth-epps
• client: Return a portion of the response body in the error message, when the client receives an unexpected non-gRPC HTTP response, to make debugging easier. (#8929)
  • Special Thanks: @chengxilo
• server: Add environment variable GRPC_GO_SERVER_GOROUTINE_LABELS that controls setting runtime/pprof.Labels on goroutines spawned by the server. Set GRPC_GO_SERVER_GOROUTINE_LABELS=grpc.method=true to add the grpc.method label on goroutines spawned to handle incoming requests. (#9082)
  • Special Thanks: @dfinkel

Bug Fixes

• xds/server: Fix a memory leak of HTTP filter instances occurring when route configurations are updated in-place during a Route Discovery Service (RDS) update. (#9138)
• grpc: In the deprecated gzip Compressor (used via the deprecated WithCompressor dial option), enforce the MaxRecvMsgSize limit on the decompressed message buffer, preventing excessive memory allocation from highly compressed payloads. (#9114)
  • Special Thanks: @evilgensec
• stats/opentelemetry: Record retry attempts, grpc.previous-rpc-attempts, at the call level and not the attempt level. (#8923)
• encoding: Ensure Close() is always called on readers returned from Compressor.Decompress if possible. (#9135)
• channelz: Fix the LastMessageSentTimestamp and LastMessageReceivedTimestamp fields in SocketMetrics to ensure they contain correct timestamp values. (#9109)

Release 1.81.1

Security

• xds/rbac: Fix a potential authorization bypass caused by incorrectly falling through URI/DNS SANs to Subject Distinguished Name (DN) when matching the authenticated principal name. With this fix, only the first non-empty identity source will be used, as per gRFC A41. (#9111)
  • Special Thanks: @al4an444

Bug Fixes

• otel: Segregate client and server RPC information used for metrics and traces, to avoid one overwriting the other. (#9081)

protoc-gen-go-grpc v1.6.2

Dependencies

• Upgrade dependencies to latest.

Release 1.81.0

Behavior Changes

• balancer/rls: Switch gauge metrics to asynchronous emission (once per collection cycle) to reduce telemetry noise and align with other gRPC language implementations. (#8808)

Dependencies

• Minimum supported Go version is now 1.25. (#8969)

Bug Fixes

• xds: Use the leaf cluster's security config for the TLS handshake instead of the aggregate cluster's config. (#8956)
• transport: Send a RST_STREAM when receiving an END_STREAM when the stream is not already half-closed. (#8832)
• xds: Fix ADS resource name validation to prevent a panic. (#8970)

New Features

• grpc/stats: Add support for custom labels in per-call metrics (gRFC A108). (#9008)
• xds: Add support for Server Name Indication (SNI) and SAN validation (gRFC A101). Disabled by default. To enable, set GRPC_EXPERIMENTAL_XDS_SNI=true environment variable. (#9016)
• xds: Add support to control which fields get propagated from ORCA backend metric reports to LRS load reports (gRFC A85). Disabled by default. To enable, set GRPC_EXPERIMENTAL_XDS_ORCA_LRS_PROPAGATION=true. (#9005)
• xds: Add metrics to track xDS client connectivity and cached resource state (gRFC A78). (#8807)
• stats/otel: Enhance grpc.subchannel.disconnections metric by adding disconnection reason to the grpc.disconnect_error label (gRFC A94). This provides granular insights into why subchannels are closing. (#8973)
• mem: Add mem.Buffer.Slice() API to slice the buffer like a slice. (#8977)
  • Special Thanks: @ash2k

Performance Improvements

• alts: Pool read buffers to lower memory utilization when sockets are unreadable. (#8964)
• transport: Pool HTTP/2 framer read buffers to reduce idle memory consumption. Currently limited to Linux for ALTS and non-encrypted transports (TCP, Unix). To disable, set GRPC_GO_EXPERIMENTAL_HTTP_FRAMER_READ_BUFFER_POOLING=false and report any issues. (#9032)

Release 1.80.0

Behavior Changes

• balancer: log a warning if a balancer is registered with uppercase letters, as balancer names should be lowercase. In a future release, balancer names will be treated as case-insensitive; see #5288 for details. (#8837)
• xds: update resource error handling and re-resolution logic (#8907)
  • Re-resolve all LOGICAL_DNS clusters simultaneously when re-resolution is requested.
  • Fail all in-flight RPCs immediately upon receipt of listener or route resource errors, instead of allowing them to complete.

Bug Fixes

• xds: support the LB policy configured in LOGICAL_DNS cluster resources instead of defaulting to pick_first. (#8733)
• credentials/tls: perform per-RPC authority validation against the leaf certificate instead of the entire peer certificate chain. (#8831)
• xds: enabling A76 ring hash endpoint keys no longer causes EDS resources with invalid proxy metadata to be NACKed when HTTP CONNECT (gRFC A86) is disabled. (#8875)
• xds: validate that the sum of endpoint weights in a locality does not exceed the maximum uint32 value. (#8899)
  • Special Thanks: @RAVEYUS
• xds: fix incorrect proto field access in the weighted round robin (WRR) configuration where blackout_period was used instead of weight_expiration_period. (#8915)
  • Special Thanks: @gregbarasch
• xds/rbac: handle addresses with ports in IP matchers. (#8990)

New Features

• ringhash: enable gRFC A76 (endpoint hash keys and request hash headers) by default. (#8922)

Performance Improvements

• credentials/alts: pool write buffers to reduce memory allocations and usage. (#8919)
• grpc: enable the use of pooled write buffers for buffering HTTP/2 frame writes by default. This reduces memory usage when connections are idle. Use the WithSharedWriteBuffer dial option or the SharedWriteBuffer server option to disable this feature. (#8957)
• xds/priority: stop caching child LB policies removed from the configuration. This will help reduce memory and cpu usage when localities are constantly switching between priorities. (#8997)
• mem: add a faster tiered buffer pool; use the experimental mem.NewBinaryTieredBufferPool function to create such pools. (#8775)

Release 1.79.3

Security

• server: fix an authorization bypass where malformed :path headers (missing the leading slash) could bypass path-based restricted "deny" rules in interceptors like grpc/authz. Any request with a non-canonical path is now immediately rejected with an Unimplemented error. (#8981)

Release 1.79.2

Bug Fixes

• stats: Prevent redundant error logging in health/ORCA producers by skipping stats/tracing processing when no stats handler is configured. (#8874)