CVE-2026-64908 in Access
Summary
by MITRE • 08/11/2026
Heap-based buffer overflow in Microsoft Office Access allows an unauthorized attacker to execute code locally.
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Analysis
by VulDB Data Team • 08/12/2026
A heap-based buffer overflow vulnerability exists in Microsoft Office Access that enables remote code execution by unauthorized attackers who can manipulate memory allocation patterns during application processing. This flaw resides in the heap memory management system where insufficient bounds checking occurs when handling user-supplied data structures, particularly within database objects and query processing components. The vulnerability stems from improper input validation mechanisms that fail to adequately verify the size and content of memory allocations, allowing attackers to overflow allocated buffer regions and overwrite adjacent memory segments including return addresses and executable code pointers.
The technical exploitation of this vulnerability requires an attacker to craft malicious Office Access database files or manipulate existing database objects in ways that trigger the vulnerable code path during normal application operation. When the affected Access application processes these malformed inputs, the heap allocation routines fail to enforce proper boundary checks, enabling memory corruption that can be leveraged to redirect program execution flow. This type of vulnerability typically maps to common weakness enumeration CWE-121 which describes heap-based buffer overflow conditions where insufficient bounds checking allows attackers to overwrite adjacent heap memory locations.
The operational impact of this vulnerability extends beyond simple code execution as it provides attackers with a local privilege escalation vector that can be used to establish persistent access to affected systems. Once successfully exploited, the attacker gains full control over the compromised Access application process and potentially the underlying operating system, making this vulnerability particularly dangerous in enterprise environments where Microsoft Office applications are widely deployed. The attack surface includes various scenarios such as opening malicious database files, executing queries against compromised data sources, or manipulating embedded objects within Access documents.
Mitigation strategies for this vulnerability should encompass multiple defensive layers including immediate deployment of Microsoft security patches and updates that address the heap overflow conditions through proper bounds checking implementations. Network segmentation and application whitelisting policies can help limit exposure by preventing unauthorized database file execution, while regular security monitoring and endpoint detection capabilities should be employed to identify potential exploitation attempts. Organizations should also implement principle of least privilege access controls to minimize potential damage from successful exploitation, ensuring that Office Access applications operate with minimal required privileges. The vulnerability aligns with attack technique T1059 in the MITRE ATT&CK framework where adversaries leverage legitimate system tools to execute malicious code, and represents a critical threat requiring immediate remediation as outlined in industry best practices for Microsoft Office security hardening.