CVE-2026-59042 in Android
Summary
by MITRE • 11/02/2026
In __pkvm_pages_to_ppages of mmu.c, there is a possible out-of-bounds write due to a race condition. This could lead to local escalation of privilege with no additional execution privileges needed. User interaction is not needed for exploitation.
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Analysis
by VulDB Data Team • 11/02/2026
The vulnerability identified in the pkvm_pages_to_ppages function within the mmu.c module represents a critical security flaw rooted in improper synchronization mechanisms during memory management operations. This specific race condition occurs when multiple threads or processes attempt to access and modify page table entries concurrently without adequate locking or atomicity guarantees. The core technical issue lies in the lack of proper mutual exclusion around the read-modify-write sequence that translates virtual pages to physical pages. When this operation is not serialized correctly, a window of opportunity opens where one thread can observe an intermediate state while another modifies it, leading to inconsistent data structures being written back to memory. This inconsistency manifests as an out-of-bounds write, allowing execution context outside the intended boundaries of allocated buffers or kernel data structures.
From a technical perspective, this flaw aligns with CWE-362, which classifies race conditions involving concurrent access and updates to a single shared resource without adequate locking. The absence of proper synchronization primitives such as spinlocks or mutexes in critical sections of memory management code is a common source of such vulnerabilities in operating system kernels. In the context of ARM Virtualization Hardware (AVH) and Protected Kernel VM (PKVM), which are designed to provide hardware-enforced isolation for virtual machines, compromising this layer undermines the fundamental security model. The mmu.c module handles crucial address translation tasks, and any corruption here can lead to arbitrary memory writes if an attacker can control the input parameters or timing of these operations.
The operational impact of this vulnerability is severe due to its potential for local privilege escalation. An unprivileged user or a compromised application running within a guest VM could potentially exploit this race condition to write data to kernel-controlled memory regions outside their allocated space. Since no additional execution privileges are required and user interaction is not needed, the attack vector is highly accessible. The attacker does not need physical access or prior high-level permissions; simply having the ability to trigger specific system calls related to memory mapping can initiate the exploit chain. Once the out-of-bounds write occurs, it may allow overwriting critical kernel structures such as function pointers, security tokens, or control flow data, leading to arbitrary code execution with kernel privileges.
This vulnerability maps directly to MITRE ATT&CK technique T1068, which covers exploitation for privilege escalation through software vulnerabilities. Specifically, it relates to sub-techniques involving memory corruption and race conditions that allow attackers to bypass access controls. The ability to escalate from a low-privilege context to kernel-level execution effectively breaks the isolation guarantees provided by PKVM. This is particularly dangerous in cloud computing environments or multi-tenant systems where VMs are expected to be strictly isolated from each other and from the host system. A successful exploit could allow an attacker to escape their virtual machine sandbox, access sensitive data belonging to other tenants, or compromise the underlying hypervisor infrastructure.
Mitigation strategies must focus on strengthening synchronization mechanisms within the memory management subsystem. Developers should implement robust locking schemes around all critical sections that modify page tables or perform address translations. Using atomic operations where appropriate can also help reduce race windows by ensuring that read-modify-write sequences are indivisible from the perspective of other processors. Additionally, fuzzing tests specifically targeting concurrency issues in mmu.c and related memory management modules should be conducted to identify similar vulnerabilities before deployment. Static analysis tools configured to detect race conditions and out-of-bounds writes can aid in early detection during the development phase.
Long-term remediation involves reviewing the entire PKVM implementation for other potential synchronization flaws, as this issue likely indicates a broader pattern of insufficient concurrency control in critical kernel paths. Implementing formal verification methods for memory management code could help prove the absence of race conditions under all possible execution scenarios. Furthermore, enabling hardware-assisted debugging features and runtime sanitizers like KASAN can assist in detecting such issues during testing phases. Organizations relying on PKVM should ensure they apply vendor-provided patches that address this specific synchronization gap promptly to maintain the integrity of their virtualized environments.