Description

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

Executive Summary

Technical Details

Mitigations

References

Additional Metadata

{
  "score": "7.8",
  "pubDate": "2026-08-11T17:18:50.567Z",
  "pubdate": "2026-08-11T17:18:50.567Z",
  "executiveSummary": "This vulnerability is classified as a heap-based buffer overflow affecting Microsoft Office.\nThe security flaw enables an unauthorized local attacker to achieve arbitrary code execution on the target system.\nThe vulnerability resides within memory management routines handling document parsing or rendering within the Office application suite.\nSuccessful exploitation compromises the confidentiality, integrity, and availability of the host system by allowing malicious payloads to execute within the security context of the logged-in user.\nThe attacker requires local access to the target machine and must trick a user into opening a specially crafted file or leverage local execution vectors to trigger the memory corruption condition.\nGiven the severity of arbitrary code execution, this vulnerability poses significant risk to enterprise environments utilizing vulnerable versions of Microsoft Office.\nRemediation requires applying official vendor patches and adhering to strict principle of least privilege methodologies.",
  "technicalDetails": "The vulnerability is a classic heap-based buffer overflow occurring during the processing of malformed data structures within Microsoft Office.\nThe root cause stems from insufficient bounds checking and validation logic when allocating and writing data to heap memory buffers during file parsing operations.\nWhen a user opens a specifically crafted malicious file, the vulnerable component attempts to read input data that exceeds the pre-allocated memory chunk size on the heap.\nThis overflow condition overwrites adjacent heap metadata or critical application data structures with attacker-controlled values.\nBy carefully manipulating the heap layout and payload contents, an attacker can achieve precise memory corruption, redirecting the application control flow to malicious shellcode.\nThe affected component involves document parsing and rendering modules within Microsoft Office that process complex file formats.\nExploitation requires the execution of local code or the manipulation of a local file by the target user, as remote network exposure is not inherently described in the primary vector.\nAuthentication requirements are minimal or absent for the local execution context, relying entirely on the interaction with the malicious file or local process.\nPrivilege requirements are limited to standard user privileges, meaning the resulting arbitrary code executes with the access rights of the current user session.\nPost-exploitation impact includes full code execution, potential escalation of privileges if auxiliary kernel or application flaws exist, installation of persistent malware, and lateral movement across the network."
}