CVE-2026-59046 in Android
Summary
by MITRE • 11/02/2026
In __pkvm_guest_relinquish_to_host of mem_protect.c, there is a possible out-of-bounds write due to improper input validation. This could lead to local denial of service 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_guest_relinquish_to_host function within mem_protect.c represents a critical memory safety issue rooted in insufficient input validation during the process of relinquishing control from a protected kernel virtual machine guest back to the host environment. This specific code path is responsible for managing state transitions and memory mappings when a secure execution context terminates or yields resources. The core technical flaw lies in the failure to rigorously validate bounds before performing write operations on data structures that manage these transitions. When an attacker can influence the parameters passed to this function, they may trigger an out-of-bounds write condition. This type of error occurs because the application does not properly verify whether a memory access is within the intended boundaries of allocated buffers or kernel data structures, allowing writes to occur in adjacent memory regions that are not meant to be modified by this operation.
From a technical perspective, this vulnerability aligns with CWE-787: Out-of-bounds Write, which describes situations where software writes data beyond the end, or before the beginning, of the intended buffer. In the context of kernel-level code such as mem_protect.c, an out-of-bounds write is particularly dangerous because it can corrupt critical kernel structures, overwrite function pointers, or alter control flow mechanisms that are not typically exposed to user-space applications. The lack of proper input validation means that maliciously crafted inputs can exploit this weakness without requiring complex exploitation techniques beyond the initial trigger. Since the vulnerability exists in a component that handles guest relinquishment, it may be triggered through specific system calls or API interactions that initiate this state change, potentially allowing an attacker to manipulate memory layout and integrity from within a restricted execution context.
The operational impact of this vulnerability is primarily characterized by local denial of service conditions. Because the out-of-bounds write can corrupt kernel memory structures essential for system stability, it often leads to immediate crashes or panics in the operating system. This results in a complete loss of availability for all services running on the affected device. While out-of-bounds writes can sometimes be leveraged for privilege escalation, the specific description indicates that local denial of service is the confirmed outcome with no additional execution privileges required. This means that any user or process capable of triggering the __pkvm_guest_relinquish_to_host function can destabilize the entire system. The absence of a requirement for user interaction further exacerbates the risk, as automated processes or background services could inadvertently trigger this condition if they interact with vulnerable components under certain conditions.
This vulnerability maps to several entries in the MITRE ATT&CK framework that describe techniques used by adversaries to disrupt service availability and exploit memory corruption flaws. Specifically, it relates to technique T1499: Endpoint Denial of Service, where an attacker uses methods such as resource exhaustion or system crashes to make a target unavailable. Additionally, the underlying flaw corresponds to CWE-787 (Out-of-bounds Write) and potentially CWE-20: Improper Input Validation, which highlights the root cause of allowing untrusted data to influence memory operations without adequate checks. Understanding these mappings helps in categorizing the severity and potential attack vectors associated with this defect within broader security assessments.
Mitigation strategies for this vulnerability must focus on both immediate patching and long-term defensive coding practices. The primary remediation is the application of a vendor-provided software update that corrects the input validation logic within mem_protect.c to ensure all memory accesses are strictly bounded by allocated limits. Developers should implement rigorous bounds checking before any write operation, ensuring that indices or offsets calculated from user-controlled inputs do not exceed buffer sizes. Furthermore, adopting static analysis tools and fuzzing techniques during the development lifecycle can help identify similar input validation gaps in other parts of the kernel codebase. Enabling compiler-based security features such as stack protectors and address space layout randomization (ASLR) may also mitigate some exploitation attempts by making it harder for attackers to predict memory layouts, although these are compensating controls rather than fixes for the root cause. Regular audits of critical system components like mem_protect.c against industry standards will help prevent recurrence of such high-severity memory safety issues.