Full Changelog: v1.6.0.0...v1.6.1.0

Matter SDK Release Notes: v1.6.1 (compared to v1.6.0)

Executive Summary

The v1.6.1 release incorporates 332 commits beyond the v1.6.0 release baseline (commit 59bb2d613a / tag v1.6.0.0). Primary changes:

• Data Model Alignment: Synchronized Matter 1.6.1 data model XML schemas (data_model/1.6.1/) via Alchemy, including Groupcast updates, Access Control AUX (Auxiliary) feature, Media File Management, Audio Control, and Basic Information DataModelRevision 21.
• Code-Driven Cluster Architecture: Continued migration of cluster implementations to DefaultServerCluster (LaundryWasherControls, OperationalState, ColorControl, ModeBase, ServiceArea).
• Memory & Transport Safety: Hardened BDX transfer bounds, UDC string and rotating ID buffer limits, CSR subject key validation, and unsolicited message handler restoration on exchange setup failures.
• Intermittently Connected Devices (ICD): Deferred ActiveMode and Check-In triggers when Thread network is detached; eliminated race conditions in commissioning stage progression.
• Reference Applications (all-devices-app): Introduced composed device infrastructure, bridged node types, compound inline configuration (,bridged), wildcard (*) instantiation, and 13 new simulated device types.
• Platform Expansions: Added support for STM32WBA; added Silicon Labs Series 3 (BRD4407A) and Zephyr factory storage/OTA; upgraded NXP Zephyr examples to Zephyr 4.4 and PSA crypto; added ESP32H4, ESP32S31, and ESP32H21 variants.
• Test Automation: Replaced multiple legacy YAML test suites with automated Python test scripts (TC-SC-3.x, TC-SMOKECO-2.x, TC-S-2.3); added automatic wildcard subscription verification in MatterBaseTest.

Key Changes by Category

1. Data Model & Cluster Specifications

• Data Model v1.6.1 Schema Updates (data_model/1.6.1/):
  • Groupcast Cluster: Updated provisional conformance rules; added GroupcastTesting commands/events, ConfigureAuxiliaryACL, and LN feature gating.
  • Access Control Cluster (ACL): Added AUX (Auxiliary) feature support for auto-generated auxiliary entries, AccessControlAuxiliaryTypeEnum, and AuxiliaryAccessUpdated event.
  • Media File Management (0x0511): Introduced cluster XML, generated stubs, and delegate server interfaces via Alchemy v1.6.20.
  • Audio Control Cluster: Added generated cluster definitions, command handlers, and attributes.
  • Content Launcher & Media Playback: Aligned cluster structures and attributes via Alchemy.
  • Closure Control & Closure Dimension: Synchronized cluster XML and implemented grouped commands.
  • CommissioningProxy (0x0750): Added initial cluster definition and generated type definitions.
  • Basic Information: Updated DataModelRevision attribute to 21 matching Matter 1.6 specification.
  • Network Commissioning: Reverted and stabilized cluster revision to 2.
• Group Key Management:
  • Implemented revision 4 with Changes Omitted (C) quality on GroupKeyMap.
  • Removed deprecated GroupKeyMulticastPolicy field from GroupKeySetStruct.
  • Fixed EndpointIterator resource leak in GroupTableCodec::Encode.
• Attribute Access & Filtering:
  • Enforced strict fabric filtering for all fabric-sensitive attribute reads.
  • Added Datamodel Errata engine support for runtime cluster revision overrides.
  • Added null pointer guards across TV-related cluster delegates.
  • Enabled subscriber notifications when ActivePresetHandle changes in Thermostat server.

2. Code-Driven Cluster Migrations

• LaundryWasherControls: Fully migrated from legacy Ember codegen to code-driven DefaultServerCluster implementation.
• OperationalState: Converted cluster server logic to code-driven interface.
• ColorControl: Executed initial decoupling phase from generated Ember stubs.
• ModeBase & ModeSelect: Decoupled cluster base and renamed implementation files to align with code-driven conventions.
• ServiceArea: Completed initial decoupling phase from legacy codegen.
• SoilMeasurement: Refactored cluster logic to code-driven architecture; fixed NXP Zephyr and Telink compilation.
• Delegates & Attributes:
  • Added external callback hooks to SmokeCoAlarmDelegate.
  • Added SafeAttribute migration compatibility logic in CameraAVStreamManagementCluster.

3. Core SDK, Protocols & Security

Transport & Interaction Model

• Exchange Management: Restored unsolicited message handler when exchange construction fails validation.
• Session Authentication: Secured session peer addresses by updating them only after incoming messages pass full cryptographic authentication.
• Transaction Consistency: Unified SuppressResponse handling across Invoke, Write, and Report transactions.
• Resource Management: Fixed heap memory leak in WriteClient during chunked write errors.
• FailSafe Timer: Increased default failsafe duration from 1s to 20s to prevent spurious timeouts over high-latency networks.
• Alignment & Types: Set CHIP_CONFIG_LAMBDA_EVENT_ALIGN based on max_align_t rather than raw pointer width.
• Class Semantics: Explicitly deleted Cancelable::operator= (Rule-of-Three completion); prevented copy operations on self-referential and span-owning helper types.

Cryptography & Credentials

• PSA Crypto: Aligned PSA P256Keypair::Serialize buffer zeroing and cleanup behavior with mbedTLS backend.
• CSR Validation: Added subject key type validation in mbedTLS CSR generation.
• PASE Protocol: Validated initiatorRandom length in HandlePBKDFParamResponse; guarded PASE fuzzing harness against uninitialized verifier dereferences.
• Credentials & DCL:
  • Updated production PAA certificates from DCL mirror (July 2026).
  • Appended SubjectKeyId to PAA certificate filenames to eliminate file collision hazards.
  • Added parser support for vendor_reserved fields in NOCSR elements.
  • Added unsigned char cast before isdigit in ASN.1 date parsing.
• Fuzzing & Sanitizers:
  • Added MemorySanitizer (MSAN) build support for fuzz targets.
  • Introduced PW/FuzzTest fuzzing harnesses for certificates, ASN.1 parsing, and BLE/BTP transport.

Groupcast Protocol

• Added LRU caching mechanism for Group Peer Table lookups.
• Ensured privacy flag is set on all outbound group messages.
• Added session ID collision avoidance and verification in group session setup.

Boundary & Buffer Protections

• BDX: Enforced rejection of BDX Accept messages when proposed MaxBlockSize is exceeded.
• UDC: Resolved off-by-one string copy in ReadPayload; eliminated uninitialized stack memory reads on oversized UDC rotating IDs.
• Identification Declaration: Bounded TargetAppInfo count against allocated buffer bounds in AddTargetAppInfo.

4. Camera, Video, Audio & Wi-Fi PAF

• PushAV Stream Transport:
  • Fixed heap buffer overflow in Push-AV transport handling.
  • Fixed double-free defect in PushAVClipRecorder.
  • Corrected DASH/CMAF MPD manifest generation to meet Push-AV specification conformance and ensure live stream playback.
• WebRTC & Media:
  • Ensured iceServers optional field is properly initialized in Requestor HandleOffer.
  • Reordered camera cluster initialization sequences to resolve startup crash conditions.
  • Fixed dangling MAC address string pointer during TargetVideoPlayerInfo copy in TV casting.
  • Added GCC compatibility fallback for __has_feature in miniaudio.
• Wi-Fi Public Action Frame (PAF):
  • Hardened error branches in Wi-Fi PAF PASE handshake.
  • Fixed null pointer dereference on double-close in WiFiPAFEndPoint.
  • Correctly initialized sequence history tracking index in WiFiPAFTP::Init.
  • Added connection establishment timer for publisher endpoints.

5. Intermittently Connected Devices (ICD)

• Network-Aware State Machine: Deferred transitions to ActiveMode and Check-In message dispatches whenever the Thread network interface is unattached.
• Commissioning Safety: Prevented commissioners from completing the ICD commissioning step upon receiving mismatched management responses.
• Configuration Defaults: Introduced ICD_SIT_POLLING_INTERVAL in common Zephyr Kconfigs.
• Platform Sleep Tuning: Removed unnecessary Wi-Fi ICD high-performance requests during commissioning on Silicon Labs; migrated SiWx broadcast filters off deprecated APIs.

6. Reference Applications & Tools

• all-devices-app Enhancements:
  • Composed & Bridged Topology: Added Bridged Node device type with automatic child naming; added compound inline syntax (e.g., device,bridged); added EndpointIdAllocator.
  • Dynamic Instantiation: Added wildcard (*) CLI expansion to spawn all simulated device configurations.
  • Device Catalog Expansion: Added 13 new simulated devices, including soil sensors, smoke/CO alarms, and Operational State appliances.
  • Audio Separation: Consolidated POSIX audio infrastructure while decoupling Chime and Speaker device layers.
  • IPC & Remote Control: Added NamedPipe support for runtime application manipulation.
  • Container Packaging: Packaged all-devices-app into chip-cert-bins Docker images.
• Other Reference Apps:
  • OTA Provider: Enforced explicit BDX transfer binding to QueryImage requester nodes.
  • Joint Fabric Admin (jf-admin-app): Fixed abort condition when a synchronized node contains non-empty binding tables; resolved unchecked nullable dereferences in JFDS.

7. Platform & BSP Updates

8. Testing, CI & Infrastructure

• Automated Python Certification Tests:
  • Replaced legacy YAML suites with Python tests: TC-SC-3.1, TC-SC-3.2, TC-SC-3.5, TC-SMOKECO-2.1–2.6, and TC-S-2.3.
  • Added automated wildcard subscription validation with C/Q attribute filtering in MatterBaseTest.
  • Added automatic command retries in Python controller upon encountering defunct secure sessions.
  • Added explicit event duplication checks and group cleanup logic in controller runtime.
  • Gated TCP support checks in TC_SEPR_2_3; adjusted TC_IDM_5_2 response timeouts to 700ms for congested testbeds.
• Continuous Integration & Automation:
  • Introduced automated platform merge checker bot (pr_checker_bot).
  • Mitigated CI runner disk space exhaustion by capping Allure report history on gh-pages and pruning host directories.
  • Added CI VM freeze detection with automatic test job restart logic.
  • Split Linux REPL test execution into 6 balanced buckets to optimize runtime.
  • Synchronized third-party submodules: Pigweed, OpenThread, ot-br-posix, lwIP, libdatachannel, and editline.

Migration & Operational Notes

1. FailSafe Timeout: The default FailSafe timeout increased from 1s to 20s. Test suites or commissioning controllers relying on the 1s default must adjust explicit timeout parameters if testing fast expiration.
2. DataModelRevision: Systems inspecting BasicInformation.DataModelRevision will observe value 21 (up from 20).
3. GroupKeyManagement Revision: GroupKeyMap now carries the Changes Omitted (C) attribute quality per revision 4. Applications monitoring group key changes via wildcard subscriptions must note this behavior.
4. Platform Maintainer Bot: Automated platform review gates now require approval from platform code owners before automated merging can proceed.