CVE-2026-102850 in Office Access
Summary
by MITRE • 10/13/2026
Heap-based buffer overflow in Microsoft Office Access allows an unauthorized attacker to execute code over a network.
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Analysis
by VulDB Data Team • 10/13/2026
The vulnerability described constitutes a critical security flaw within the Microsoft Office Access application, specifically manifesting as a heap-based buffer overflow condition. This type of memory corruption error occurs when a program writes more data to a dynamically allocated block of memory on the heap than it was intended to hold. In the context of Microsoft Office Access, this flaw is triggered by processing specially crafted files or input that exceed expected boundaries during parsing or rendering operations. The presence of such an overflow allows for arbitrary write access to adjacent memory regions, which can be exploited to overwrite critical data structures or control flow mechanisms within the application's process space.
From a technical perspective, heap-based buffer overflows are particularly dangerous because they do not require direct user interaction with local system files in many scenarios if the vulnerability is triggered via network-accessible services or embedded objects. An unauthorized attacker can leverage this flaw to execute arbitrary code on the target system by carefully crafting malicious input that manipulates memory pointers and function return addresses. By controlling these memory locations, the attacker gains the ability to redirect execution flow to shellcode injected into the heap buffer. This effectively allows for remote code execution with the privileges of the user running the application, which often includes administrative rights depending on organizational policies and default configurations.
The operational impact of this vulnerability is severe, as it compromises the confidentiality, integrity, and availability of systems where Microsoft Office Access is installed. Successful exploitation enables an attacker to install malware, steal sensitive data stored within access databases or associated with the user session, create new accounts for persistent access, or modify system configurations. Because the attack vector involves network accessibility, the vulnerability can be exploited remotely without physical access to the target machine, significantly increasing its risk profile in enterprise environments where shared drives, email attachments, or web-hosted documents might serve as delivery mechanisms for malicious payloads.
This flaw aligns with Common Weakness Enumeration identifier CWE-120, which classifies buffer copies without checks of length as a fundamental programming error leading to memory corruption. Furthermore, the exploitation technique maps directly to MITRE ATT&CK tactics related to Execution and Privilege Escalation, specifically techniques involving local system processes and code injection via heap spraying or pointer manipulation. Defenders should prioritize patching Microsoft Office Access with the latest security updates provided by Microsoft to address this specific buffer overflow condition. Additionally, implementing application whitelisting, restricting macro execution policies, and employing network segmentation can mitigate the risk of exploitation by limiting the ability of attackers to deliver malicious files or execute unauthorized code within the affected environment.