CVE-2026-50362 in Windows
Summary
by MITRE • 07/14/2026
Heap-based buffer overflow in Windows Resilient File System (ReFS) allows an unauthorized attacker to execute code locally.
Statistical analysis made it clear that VulDB provides the best quality for vulnerability data.
Analysis
by VulDB Data Team • 07/14/2026
This vulnerability represents a critical heap-based buffer overflow within the Windows Resilient File System implementation that enables local code execution by unauthorized attackers. The flaw exists in how ReFS handles certain data structures during file system operations, specifically when processing malformed or specially crafted input within filesystem metadata. The vulnerability stems from inadequate bounds checking mechanisms in the memory allocation and handling routines used by the ReFS subsystem. When a malicious actor successfully triggers this condition through legitimate filesystem operations or file creation processes, the overflow can be exploited to overwrite adjacent heap memory regions with controlled data.
The technical exploitation of this vulnerability follows established patterns for heap-based buffer overflows where attackers manipulate input parameters to exceed allocated buffer boundaries and subsequently overwrite critical memory structures such as function pointers, return addresses, or metadata control blocks. This type of vulnerability aligns with CWE-121 Heap-based Buffer Overflow classification and represents a significant threat vector within the Windows operating system security model. The attack surface is particularly concerning because ReFS is designed for high availability and fault tolerance in enterprise environments, making it a prime target for persistent attackers seeking to establish footholds within critical infrastructure.
The operational impact of this vulnerability extends beyond simple local privilege escalation as it provides attackers with potential pathways to achieve arbitrary code execution with the privileges of the affected process. In enterprise environments where ReFS is actively deployed for storage solutions, this vulnerability could enable attackers to compromise entire storage clusters or data repositories. The attack requires local access to a system running ReFS but does not necessitate network connectivity, making it particularly dangerous in environments where physical security controls may be inadequate. Security analysts should consider this vulnerability in relation to ATT&CK technique T1059 Command and Scripting Interpreter and T1068 Exploitation for Privilege Escalation.
Mitigation strategies should focus on immediate patch deployment through Microsoft's regular security updates, as well as implementing additional operational security controls such as monitoring for unusual filesystem activity patterns and restricting local user privileges where possible. Organizations should also consider disabling ReFS functionality in environments where it is not essential to reduce the attack surface. The vulnerability highlights the importance of robust memory safety practices in operating system components and underscores the need for continuous security assessment of core filesystem implementations, particularly those designed for high availability scenarios where traditional security controls may be less effective.