CVE-2026-82926 Overview
CVE-2026-82926 is a NULL pointer dereference vulnerability [CWE-476] in Samsung Open Source mTower, a trusted execution environment (TEE) implementation for IoT devices. The flaw allows an attacker with local access to trigger pointer manipulation, resulting in denial of service. The issue affects all mTower builds prior to commit afef59aa6f55c5d5ebf9b14bc020bf1c2c37489a.
Critical Impact
Local attackers can crash the mTower trusted execution environment through pointer manipulation, disrupting availability of security-sensitive workloads running inside the TEE.
Affected Products
- Samsung Open Source mTower (all versions before commit afef59aa6f55c5d5ebf9b14bc020bf1c2c37489a)
- IoT and embedded devices integrating mTower as their trusted execution environment
- Downstream firmware builds that vendor mTower components without applying the upstream fix
Discovery Timeline
- 2026-09-01 - CVE-2026-82926 published to NVD
- 2026-09-01 - Last updated in NVD database
Technical Details for CVE-2026-82926
Vulnerability Analysis
The vulnerability resides in Samsung's mTower, an open source trusted execution environment that runs alongside a rich operating system on ARM TrustZone-enabled hardware. A code path in mTower dereferences a pointer without first validating that it is non-null. When an attacker supplies input that causes the pointer to remain unset, the subsequent dereference triggers an exception inside the secure world.
Because mTower executes privileged trusted applications, a fault inside the TEE can halt cryptographic operations, key storage services, and attestation workflows. The vulnerability does not expose data or allow code execution; the confidentiality and integrity impact remain unaffected. Availability, however, is fully compromised because the trusted application terminates unexpectedly.
Exploitation requires local access and user interaction, which limits remote exposure. An attacker running an untrusted application in the normal world can invoke a client API call into the vulnerable trusted service and pass crafted parameters that reach the flawed code path.
Root Cause
The root cause is missing input validation before pointer dereference [CWE-476]. The trusted application does not verify pointer arguments passed across the secure monitor call (SMC) boundary before accessing the target memory. The upstream fix in commit afef59aa6f55c5d5ebf9b14bc020bf1c2c37489a introduces the missing null check.
Attack Vector
An attacker with local access invokes the affected trusted application interface from the normal world and passes parameters that cause an unassigned or explicitly null pointer to reach the vulnerable function. The trusted OS then dereferences the pointer, aborting the secure operation and disrupting dependent services. See the Samsung mTower Pull Request #248 for the specific code path and patch details.
No verified public exploit code is available for this issue. The vulnerability manifests through malformed parameters supplied to the TEE client API rather than through a network-reachable interface.
Detection Methods for CVE-2026-82926
Indicators of Compromise
- Unexpected termination or panic messages from the mTower trusted OS in device logs
- Repeated failures of trusted application invocations from userspace clients
- Secure world exception traces referencing null address access during TEE syscalls
Detection Strategies
- Review firmware build manifests to identify mTower revisions preceding commit afef59aa6f55c5d5ebf9b14bc020bf1c2c37489a
- Instrument the TEE client API to log parameter values passed across the secure monitor call boundary
- Correlate trusted application crashes with the local process invoking the affected client API
Monitoring Recommendations
- Forward device kernel and TEE logs to a centralized log store for anomaly analysis
- Alert on repeated secure world exceptions or trusted application restarts on the same device
- Track firmware inventory to confirm patched mTower commits are deployed across the fleet
How to Mitigate CVE-2026-82926
Immediate Actions Required
- Rebuild firmware images from mTower sources at or after commit afef59aa6f55c5d5ebf9b14bc020bf1c2c37489a
- Roll patched firmware to all affected IoT and embedded devices through the standard update channel
- Restrict which local applications may invoke trusted application client APIs on affected devices
Patch Information
The upstream fix is available in the Samsung mTower repository through Pull Request #248. Integrators must pull commit afef59aa6f55c5d5ebf9b14bc020bf1c2c37489a or later and rebuild dependent firmware. There is no runtime patch; the correction ships as source code and must be compiled into the trusted OS image.
Workarounds
- Limit local user access to devices running vulnerable mTower builds until firmware updates are applied
- Disable or gate access to non-essential trusted applications that expose the affected client API
- Monitor for and automatically restart failed trusted applications to reduce sustained denial of service impact
# Configuration example
# Verify the mTower source tree includes the fix commit before building firmware
git -C mTower log --oneline | grep afef59aa6f55c5d5ebf9b14bc020bf1c2c37489a
git -C mTower describe --contains afef59aa6f55c5d5ebf9b14bc020bf1c2c37489a
Disclaimer: This content was generated using AI. While we strive for accuracy, please verify critical information with official sources.
