Description

Out-of-bounds read in Microsoft Office allows an unauthorized attacker to disclose information locally.

Executive Summary

Technical Details

Mitigations

References

Additional Metadata

{
  "score": "5.5",
  "pubDate": "2026-08-11T17:18:49.143Z",
  "pubdate": "2026-08-11T17:18:49.143Z",
  "executiveSummary": "An out-of-bounds read vulnerability has been identified within Microsoft Office. This security defect enables an unauthorized, locally authenticated attacker to induce memory disclosure, potentially exposing sensitive system or application data to unauthorized entities.\nThe vulnerability resides within the internal data parsing and memory management routines of Microsoft Office components. By tricking a victim into processing a specially crafted file or document locally, an attacker can trigger the out-of-bounds read condition.\nThe primary impact of successful exploitation is localized information disclosure. Depending on the memory contents exposed during the read operation, sensitive data such as heap allocations, credentials, or internal application structures may be leaked to the adversary.\nThe risk implication is rated as moderate, primarily constrained by the requirement for local access or user interaction to open the malicious document. No elevated privileges are strictly required for the attacker to execute the initial local reconnaissance or trigger the condition.\nMitigation relies heavily on applying official vendor patches and adhering to strict administrative controls regarding the handling of untrusted documents received from external or unverified sources.",
  "technicalDetails": "The vulnerability is fundamentally rooted in an out-of-bounds read flaw within the memory handling and parsing architecture of Microsoft Office. The affected component fails to adequately validate input boundaries and buffer sizes when parsing specific file structures or document attributes.\nDuring standard execution, Microsoft Office components allocate buffers based on internal size descriptors or metadata embedded within processed files. If a file is maliciously crafted to manipulate these size indicators, the parsing engine may attempt to read memory addresses beyond the intended boundaries of the allocated buffer.\nExploitation requires the attacker to deliver a specially crafted file to the target system and induce a local user or process to open it using a vulnerable version of Microsoft Office. This attack flow bypasses standard input sanitization because the malformed parameters exploit logical flaws in boundary checks rather than classical buffer overflows.\nUpon processing the malicious structure, the vulnerable function reads adjacent memory blocks from the heap or stack, depending on the specific subsystem involved. If the application exposes the results of this read operation back to the user interface, error logs, or debugging outputs, the attacker can harvest the leaked memory contents.\nThe technical requirements for this attack involve local access to the target host and user interaction to open the crafted file. The vulnerability does not inherently provide remote code execution capabilities; its post-exploitation impact is strictly confined to unauthorized local information disclosure of residual memory contents."
}