CVE-2026-0428: TEE SOC Driver RCE Vulnerability

CVE-2026-0428 Overview

CVE-2026-0428 is an input validation vulnerability in the AMD Trusted Execution Environment (TEE) System-on-Chip (SOC) Driver. The driver fails to adequately sanitize parameters supplied through the DRV_SOC_CMD_ID_SRIOV_COPY_VF_CHIPLET_REGS command. An attacker with high privileges and local access can issue a malformed command to write invalid data to a remote Die. This may result in unexpected behavior on the affected system. The flaw is classified under CWE-1284: Improper Validation of Specified Quantity in Input. AMD disclosed the issue in AMD Security Bulletin #6027.

Critical Impact

A local attacker with high privileges can submit a malformed TEE SOC driver command to corrupt register state on a remote Die, producing unpredictable system behavior.

Affected Products

• AMD processors implementing the TEE SOC Driver with SR-IOV chiplet register copy support
• Refer to AMD Security Bulletin #6027 for the authoritative list of affected SKUs
• Specific product CPE entries were not published in the NVD record at time of writing

Discovery Timeline

• 2026-05-15 - CVE-2026-0428 published to NVD
• 2026-05-15 - Last updated in NVD database

Technical Details for CVE-2026-0428

Vulnerability Analysis

The vulnerability resides in the AMD TEE SOC Driver, a privileged firmware component that mediates access to System-on-Chip control surfaces. The driver exposes the DRV_SOC_CMD_ID_SRIOV_COPY_VF_CHIPLET_REGS command, which copies Virtual Function (VF) chiplet registers in Single-Root I/O Virtualization (SR-IOV) configurations. The command handler does not fully validate parameters supplied by the caller. A caller can craft a malformed request that causes the driver to write invalid data to a remote Die, which is a separate silicon module within multi-die AMD processor packages. The result is unexpected behavior in the targeted Die, which may include incorrect register state or instability in downstream operations. Exploitation requires local access and high privileges, narrowing the realistic attacker population to administrators or compromised privileged processes.

Root Cause

The root cause is insufficient parameter sanitization in the command handler for DRV_SOC_CMD_ID_SRIOV_COPY_VF_CHIPLET_REGS. The driver trusts caller-supplied values that influence the destination of a register write across Dies. Without proper bounds and type validation, malformed inputs reach the cross-Die write path. This pattern maps to [CWE-1284], where the implementation fails to validate a specified quantity meets expected constraints before use.

Attack Vector

The attack vector is local. An attacker requires high privileges on the host to interact with the TEE SOC Driver interface. After obtaining the necessary handle, the attacker issues the vulnerable command with crafted parameters. The malformed write targets a remote Die and corrupts register state. There is no impact on confidentiality or integrity as scored, but availability of the affected component may degrade.

No public proof-of-concept code is available. See AMD Security Bulletin #6027 for vendor-supplied technical detail.

Detection Methods for CVE-2026-0428

Indicators of Compromise

• Unexpected hardware faults, machine check exceptions, or Die-level instability following privileged driver activity
• Privileged process invocations issuing TEE SOC driver IOCTLs outside of normal platform management workflows
• System event logs recording abnormal SR-IOV virtual function register operations

Detection Strategies

• Audit privileged process activity that interacts with AMD TEE SOC driver interfaces and correlate with platform stability events
• Establish a baseline of legitimate callers of DRV_SOC_CMD_ID_SRIOV_COPY_VF_CHIPLET_REGS and flag deviations
• Correlate machine check architecture (MCA) events with preceding administrative actions to identify suspicious sequences

Monitoring Recommendations

• Forward kernel and platform firmware logs to a centralized analytics tier for retrospective hunting
• Track integrity of administrative accounts that hold the privileges required to reach the driver interface
• Monitor for unexpected reboots or Die-level resets on AMD SR-IOV hosts

How to Mitigate CVE-2026-0428

Immediate Actions Required

• Review AMD Security Bulletin #6027 and identify affected processor SKUs in your fleet
• Apply AMD-supplied firmware or microcode updates as they become available for impacted platforms
• Restrict administrative access to hosts running affected AMD processors with SR-IOV enabled

Patch Information

AMD provides remediation guidance through AMD Security Bulletin #6027. Consult that advisory for firmware version numbers, microcode revisions, and platform-specific update procedures. Coordinate with hardware vendors and hypervisor providers to obtain integrated platform updates.

Workarounds

• Limit local high-privilege access on affected systems through strong access control and just-in-time administration
• Disable SR-IOV on workloads that do not require it until patched firmware is deployed
• Apply hardware vendor BIOS or UEFI updates that incorporate AMD's fix once published