Description

Use of uninitialized resource in Microsoft Office allows an unauthorized attacker to disclose information locally.

Executive Summary

Technical Details

Mitigations

References

Additional Metadata

{
  "score": "5.5",
  "pubDate": "2026-08-11T17:19:09.170Z",
  "pubdate": "2026-08-11T17:19:09.170Z",
  "executiveSummary": "This vulnerability involves an uninitialized resource condition within Microsoft Office, which permits an unauthorized attacker to achieve local information disclosure. The flaw exposes sensitive data residing in memory or local storage through improper handling of system resources during application execution. Impacted systems are limited to the specific Microsoft Office products utilized locally on the target machine. The primary risk implication centers on the unauthorized extraction of confidential information, potentially exposing sensitive documents, user credentials, or internal system data to local threat actors. Attacker capabilities are restricted to unauthorized data access without requiring elevated administrative privileges. Exploitation typically requires local access to the vulnerable system or user interaction to process a specially crafted file that triggers the uninitialized resource state. Due to the local nature of the vulnerability, network exposure is not a primary vector, but successful exploitation allows threat actors to gather intelligence necessary for subsequent multi-stage attacks within the environment.",
  "technicalDetails": "The root cause of the vulnerability stems from the improper initialization of a resource within the Microsoft Office codebase. When the application allocates memory or handles system resources during document parsing or rendering operations, the execution path encounters a state where a resource is referenced or utilized prior to explicit initialization. This programming oversight leads to undefined behavior, where residual data left in memory from previous processes or unrelated operations remains accessible to the application context.\nThe vulnerable component resides within the core parsing and resource management modules of Microsoft Office. Exploitation occurs when an unauthorized local attacker induces the application to process a malformed or specially crafted file. Step-by-step, the attack flow initiates when the victim opens the malicious file using the affected Microsoft Office product. As the software parses the structure and allocates internal buffers, the application fails to properly initialize specific memory structures or resource handles. Due to the uninitialized state, subsequent read operations executed by the application inadvertently capture residual data residing within those memory segments. The attacker then leverages this flaw to read the disclosed information, which may contain sensitive context such as system metadata, memory pointers, or fragments of previously processed documents.\nRegarding authentication and privilege requirements, the exploitation vector does not mandate advanced authentication mechanisms or elevated privileges. Because the vulnerability manifests locally, the attacker must have local execution capabilities or the ability to deliver the crafted file to the target user. Network exposure is absent, as the attack vector relies purely on local file processing rather than remote network services or socket communications. The payload behavior is strictly passive from a persistence standpoint, focusing exclusively on reading and leaking data rather than executing arbitrary code or establishing persistence mechanisms. The post-exploitation impact is characterized by localized information disclosure, granting the attacker visibility into sensitive data structures and potentially facilitating reconnaissance for further compromise."
}