CVE-2026-0028 Overview
CVE-2026-0028 is an integer overflow vulnerability in the __pkvm_host_share_guest function of Google Android's mem_protect.c kernel component. This vulnerability enables an out-of-bounds write condition that can be exploited for local privilege escalation without requiring any additional execution privileges or user interaction.
The vulnerability exists in the Protected Kernel-based Virtual Machine (pKVM) memory protection subsystem, which is responsible for managing memory isolation between the host and guest virtual machines. An attacker with local access to an affected Android device can exploit this integer overflow to corrupt kernel memory and escalate privileges to gain full control of the device.
Critical Impact
Local privilege escalation with no user interaction required, enabling complete device compromise on affected Android systems.
Affected Products
- Google Android (all versions prior to March 2026 security patch)
Discovery Timeline
- 2026-03-02 - CVE-2026-0028 published to NVD
- 2026-03-03 - Last updated in NVD database
Technical Details for CVE-2026-0028
Vulnerability Analysis
The vulnerability resides in the __pkvm_host_share_guest function within mem_protect.c, a critical component of Android's pKVM hypervisor implementation. pKVM provides memory isolation guarantees for protected virtual machines running on Android devices, making this vulnerability particularly significant for enterprise and security-focused deployments.
The integer overflow occurs during memory size calculations when the host attempts to share memory with a guest virtual machine. When specific boundary conditions are triggered, arithmetic operations on memory size parameters wrap around, resulting in a much smaller allocation than expected. Subsequent memory operations then write beyond the allocated buffer boundaries.
This out-of-bounds write condition allows an attacker to corrupt adjacent kernel memory structures. Given the privileged context in which this code executes, successful exploitation enables arbitrary code execution at the kernel level, effectively granting the attacker complete control over the affected device.
The local attack vector means an attacker needs either physical access to the device or the ability to execute code through a malicious application. However, the lack of required privileges and user interaction makes this vulnerability particularly dangerous for mobile threat scenarios.
Root Cause
The root cause is classified as CWE-190 (Integer Overflow or Wraparound). The __pkvm_host_share_guest function fails to properly validate integer arithmetic operations before using the computed values for memory allocation. When attacker-controlled or boundary-case input values cause the multiplication or addition of size parameters to exceed the maximum representable integer value, the result wraps around to a small positive number.
This miscalculated size is then used to allocate a buffer that is significantly smaller than required. When the function subsequently attempts to write data based on the original (non-wrapped) size calculations, the write operation exceeds the buffer boundaries, corrupting adjacent memory.
Attack Vector
The attack vector is local, requiring the attacker to execute code on the target Android device. This could be achieved through:
A malicious application installed on the device can invoke kernel functionality that triggers the vulnerable code path in __pkvm_host_share_guest. The attacker crafts specific memory sharing requests with size parameters designed to trigger the integer overflow condition.
Once the overflow occurs, the out-of-bounds write corrupts kernel data structures. A sophisticated attacker can leverage this corruption to achieve arbitrary code execution in the kernel context, completely bypassing Android's security model including SELinux, seccomp, and application sandboxing.
The vulnerability affects the pKVM subsystem, which is used in Android's virtualization-based security features. Devices using protected virtual machines for sensitive workloads are at elevated risk.
Detection Methods for CVE-2026-0028
Indicators of Compromise
- Unexpected kernel crashes or system instability that may indicate exploitation attempts
- Suspicious applications requesting unusual memory-related system calls
- Evidence of privilege escalation from untrusted application contexts
- Kernel log entries showing memory corruption or invalid memory access patterns
Detection Strategies
- Monitor for applications attempting to interact with pKVM or hypervisor interfaces
- Implement behavioral analysis to detect anomalous memory allocation patterns
- Deploy endpoint detection to identify known exploitation techniques targeting kernel memory corruption
- Review installed applications for unknown or suspicious packages with native code components
Monitoring Recommendations
- Enable kernel auditing to log memory protection subsystem activities
- Configure crash dump collection for forensic analysis of potential exploitation
- Monitor device security patch levels across the fleet to identify vulnerable systems
- Implement mobile threat defense solutions capable of detecting privilege escalation attempts
How to Mitigate CVE-2026-0028
Immediate Actions Required
- Apply the March 2026 Android Security Patch immediately on all affected devices
- Audit installed applications and remove any untrusted or unnecessary software
- Enable Google Play Protect to scan for potentially harmful applications
- Consider restricting device provisioning until patches are applied in enterprise environments
Patch Information
Google has released multiple kernel commits to address CVE-2026-0028 as part of the March 2026 Android Security Bulletin. The patches add proper integer overflow checking before memory allocation operations in the __pkvm_host_share_guest function.
The following kernel commits resolve this vulnerability:
Device manufacturers should incorporate these patches into their device-specific kernel builds. End users should ensure their devices are updated to the March 2026 security patch level or later. Refer to the Android Security Bulletin March 2026 for complete details.
Workarounds
- Limit installation of applications to trusted sources only (Google Play Store with Play Protect enabled)
- Avoid sideloading APKs from unknown or untrusted sources
- Consider using Android Enterprise device management to restrict application installation
- For high-security environments, isolate unpatched devices from sensitive resources until updates are applied
Disclaimer: This content was generated using AI. While we strive for accuracy, please verify critical information with official sources.
