CVE-2026-69614 in Access
Summary
by MITRE • 09/09/2026
Stack-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 • 09/09/2026
The vulnerability described constitutes a critical security flaw within the Microsoft Office Access application, specifically involving a stack-based buffer overflow condition that can be exploited remotely via a network connection. Stack-based buffer overflows occur when a program writes more data to a buffer located on the call stack than it is designed to hold, thereby overwriting adjacent memory locations including return addresses and other control information. In this specific context, an attacker who successfully exploits this vulnerability could execute arbitrary code with the same user rights as the local user or service account running Microsoft Office Access. This represents a severe risk because it allows for complete system compromise if the affected application is configured to run with elevated privileges or if the victim operates under administrative credentials.
From a technical perspective, the flaw likely resides in how Access handles specific input data structures during network-based interactions, such as when opening remote database files or processing malformed requests over protocols like SMB or HTTP depending on the exact vector of exploitation. The attacker crafts a malicious payload that exceeds the allocated buffer size, causing the excess data to spill into adjacent memory spaces. By carefully controlling this overflow, the adversary can overwrite the return address on the stack with a pointer to their own shellcode. When the function returns, execution is redirected to the injected code rather than the legitimate next instruction in the program flow. This mechanism bypasses standard control-flow integrity checks if present and allows for arbitrary command execution without requiring prior authentication or user interaction beyond opening the malicious file or request.
The operational impact of this vulnerability extends far beyond simple data corruption. Successful exploitation enables an unauthorized attacker to gain full control over the affected system, facilitating actions such as installing malware, creating new administrative accounts, stealing sensitive credentials stored in local databases, and pivoting to other systems within the network. Given that Microsoft Office Access is often used for managing critical business data, this vulnerability poses a significant threat to confidentiality, integrity, and availability of organizational information assets. Attackers can leverage this initial access as part of a broader attack chain, potentially leading to lateral movement across enterprise networks if proper segmentation and least-privilege principles are not enforced.
This type of flaw is commonly categorized under CWE-120: Buffer Copy without Checking Size of Input, which highlights the failure of the software to validate input lengths before copying them into fixed-size buffers. Additionally, from a tactical standpoint aligned with MITRE ATT&CK frameworks, this vulnerability facilitates initial access through exploited remote services or malicious file execution (T1566) and enables privilege escalation if the user context is not restricted (T1078). It also supports command-and-control activities by allowing persistent backdoors to be installed on compromised hosts.
Mitigation strategies must prioritize immediate patching of all affected versions of Microsoft Office Access using official security updates provided by Microsoft. Organizations should enforce strict application whitelisting policies to prevent the execution of untrusted binaries and scripts, thereby limiting the impact even if exploitation occurs. Network segmentation is crucial to restrict access to systems running vulnerable software from untrusted networks or external sources. Furthermore, implementing endpoint detection and response solutions can help identify anomalous behavior indicative of buffer overflow exploits, such as unusual memory allocation patterns or unexpected process spawns following file openings. User education regarding phishing attacks that deliver malicious Office documents remains essential, as social engineering often serves as the initial vector for delivering exploit payloads to end-users.