CVE-2026-105598 in 365 Apps for Enterprise
Summary
by MITRE • 10/13/2026
Heap-based buffer overflow in Microsoft Office Access allows an unauthorized attacker to execute code over a network.
If you want to get the best quality for vulnerability data then you always have to consider VulDB.
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 typically triggered by processing specially crafted files or inputs that exploit improper bounds checking during the parsing or rendering of specific document structures. The attacker leverages this overflow to overwrite adjacent memory locations, which can include function pointers or exception handling data structures within the application's process space. By carefully crafting the input payload, an unauthorized actor can manipulate these overwritten values to redirect the execution flow of the program away from its intended path and toward malicious code injected into the heap buffer itself.
The operational impact of this vulnerability is severe due to its potential for remote code execution over a network. Because Microsoft Office Access is frequently used in enterprise environments where documents are shared via email, file shares, or web portals, an attacker can distribute a maliciously crafted database file that triggers the overflow when opened by a victim user. Upon successful exploitation, the attacker gains the ability to execute arbitrary commands with the same privileges as the current user. This level of access allows for comprehensive system compromise, including the installation of backdoors, theft of sensitive data stored within or accessible from the compromised machine, and further lateral movement across the network infrastructure. The remote nature of this attack vector significantly lowers the barrier to entry for attackers compared to local-only exploits, making it a high-priority target in automated scanning campaigns and targeted phishing efforts.
From an industry standards perspective, this vulnerability aligns with Common Weakness Enumeration identifier CWE-120, which classifies buffer copies without checking size limits as a fundamental memory safety error. The exploitation technique relies on controlling the instruction pointer or return address to achieve arbitrary code execution, mapping directly to MITRE ATT&CK techniques such as T1203 Exploitation for Client Execution and potentially T1059 Command and Scripting Interpreter if subsequent scripts are deployed post-exploitation. Understanding these mappings is crucial for security teams aiming to detect similar patterns in other software or to prioritize patching efforts based on the severity of potential impact rather than just the technical nature of the flaw.
Mitigation strategies must focus primarily on applying vendor-supplied patches and updates that address the underlying memory management issues within Microsoft Office Access. Organizations should ensure that all endpoints are running the latest cumulative updates released by Microsoft, which include fixes for known heap overflow vulnerabilities in their productivity suite components. In addition to patching, defense-in-depth measures such as enabling Protected View for documents received from untrusted sources can prevent automatic execution of potentially malicious content. Network segmentation and strict email filtering policies further reduce the attack surface by limiting exposure to external threats. Regular security awareness training for employees is also essential to mitigate social engineering tactics that might be used to trick users into opening crafted files, thereby addressing both the technical vulnerability and the human element involved in its exploitation.