CVE-2025-56362 Overview
CVE-2025-56362 is a reachable assertion vulnerability in the Matter SDK (connectedhomeip) before version 1.4.2. The flaw resides in the Level Control cluster's periodic server tick logic. An unauthenticated remote attacker can trigger the assertion currentLevel < maxLevel by sending a MoveToLevel command immediately followed by a write of OperationMode=2 to the Pump Configuration and Control cluster. The violated assertion crashes the server, producing a denial of service on any Matter-compliant device built with the affected SDK versions. The vulnerability is tracked under CWE-617: Reachable Assertion.
Critical Impact
Unauthenticated remote attackers can crash Matter-enabled smart home and IoT devices with a two-message sequence, disrupting availability across affected deployments.
Affected Products
- Connectivity Standards Alliance (CSA) Matter SDK (connectedhomeip) version 1.3
- Connectivity Standards Alliance (CSA) Matter SDK (connectedhomeip) version 1.4 (commit ab3d5ae)
- All Matter SDK builds prior to 1.4.2 that implement the Level Control cluster alongside the Pump Configuration and Control cluster
Discovery Timeline
- 2026-07-14 - CVE-2025-56362 published to the National Vulnerability Database (NVD)
- 2026-07-17 - Last updated in NVD database
Technical Details for CVE-2025-56362
Vulnerability Analysis
The Matter SDK provides the reference implementation for the Matter smart-home interoperability standard maintained by the Connectivity Standards Alliance. Its Level Control cluster manages device attributes such as brightness, position, or pump speed, while the Pump Configuration and Control cluster governs pump behavior including operation mode.
The defect surfaces in the periodic server tick handler that advances the Level Control state machine after a MoveToLevel command. The tick logic depends on the invariant currentLevel < maxLevel. Writing OperationMode=2 to the Pump Configuration and Control cluster in the middle of a MoveToLevel transition mutates the effective range so that currentLevel is no longer strictly less than maxLevel. The next server tick triggers the assertion, aborting the process.
The outcome is a hard crash of the Matter server process. Because Matter devices typically host a single application instance, the crash removes the device from the fabric until it restarts.
Root Cause
The root cause is an unsafe assumption in the Level Control periodic tick: it asserts a bound that external cluster writes can invalidate. The assertion is used as a control-flow check rather than a runtime guard, so a legitimate but unexpected attribute state converts a recoverable condition into a fatal termination. This matches the CWE-617 pattern of a reachable assertion invoked with attacker-influenced inputs.
Attack Vector
Exploitation requires network reachability to a Matter node and no authentication, per the published CVSS vector. An attacker on the local Matter fabric sends two operationally valid messages:
- A MoveToLevel command to the Level Control cluster.
- An immediate write of OperationMode=2 to the Pump Configuration and Control cluster on the same endpoint.
The server tick then evaluates the violated invariant and aborts. No memory corruption or code execution is achieved; the impact is limited to availability. Full technical discussion is tracked in the upstream GitHub Issue #38618 Discussion.
Detection Methods for CVE-2025-56362
Indicators of Compromise
- Unexpected process aborts or restarts on Matter devices logged with assertion messages referencing currentLevel and maxLevel in the Level Control cluster.
- Matter fabric events showing a node dropping offline immediately after receiving a MoveToLevel command followed by an OperationMode write.
- Repeated crash-loop behavior on devices exposing both the Level Control and Pump Configuration and Control clusters on the same endpoint.
Detection Strategies
- Inspect Matter application logs for assert or VerifyOrDie failures originating in Level Control cluster source files.
- Correlate device availability drops with inbound Matter cluster commands to identify the two-message trigger sequence.
- Baseline normal command frequency per endpoint and alert on rapid MoveToLevel followed by OperationMode writes from the same source node.
Monitoring Recommendations
- Forward Matter device syslog and crash dumps to a centralized logging platform for retention and correlation.
- Monitor Matter fabric membership changes and unplanned reboots per device to surface abuse patterns early.
- Track the SDK version deployed on each Matter product in asset inventory to prioritize devices still on 1.3 or 1.4.
How to Mitigate CVE-2025-56362
Immediate Actions Required
- Upgrade all Matter devices and reference builds to connectedhomeip 1.4.2 or later.
- Identify devices exposing both the Level Control and Pump Configuration and Control clusters and prioritize their patching.
- Restrict Matter fabric membership to trusted commissioned devices and remove unused or unknown nodes.
Patch Information
The fix is available in Matter SDK 1.4.2. Vendors integrating connectedhomeip should rebuild firmware against the patched release and distribute updated images through their standard OTA channel. Source and release notes are published at the Connected Home IP GitHub repository.
Workarounds
- Segment Matter devices on a dedicated network segment or VLAN to limit exposure to untrusted hosts.
- Where feasible, disable the Pump Configuration and Control cluster on endpoints that do not require it until patched firmware is available.
- Enable automatic device restart or watchdog recovery to reduce downtime if the assertion is triggered before patching completes.
# Verify the installed Matter SDK version against the fixed release
git -C connectedhomeip describe --tags
# Expected output: v1.4.2 or later
Disclaimer: This content was generated using AI. While we strive for accuracy, please verify critical information with official sources.
