CVE-2026-69719 in Office
Summary
by MITRE • 09/09/2026
Buffer over-read in Microsoft Office Word allows an unauthorized attacker to disclose information over a network.
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Analysis
by VulDB Data Team • 09/09/2026
The vulnerability identified involves a buffer over-read condition within the document parsing engine of Microsoft Office Word, specifically affecting how certain file formats are processed during rendering or preview operations. This flaw arises when the application fails to properly validate boundary conditions while reading data from memory buffers associated with malformed or specially crafted documents. Instead of causing an access violation that would typically crash the application, this specific implementation error allows the attacker to read arbitrary memory contents beyond the intended buffer limits. The primary consequence of this technical deficiency is the unauthorized disclosure of sensitive information residing in the process space of the Word application at the time of exploitation.
From a technical perspective, this issue falls under the category of CWE-125, which describes Out-of-bounds Read vulnerabilities. In such scenarios, an attacker can leverage the over-read to extract data that was not intended for public access, potentially including cryptographic keys, session tokens, or other confidential user data stored in memory. The operational impact is significant because it enables information leakage without requiring direct code execution on the target system. This characteristic distinguishes it from more severe vulnerabilities like remote code execution, yet it remains critical as it compromises confidentiality and can facilitate further attacks by providing attackers with valuable intelligence about the victim's environment or active sessions.
The attack vector for this vulnerability is typically network-based if an attacker can trick a user into opening a malicious document via email, instant messaging, or web browsing scenarios where Word automatically parses content. This aligns with ATT&CK technique T1005, which refers to Data from Local System, specifically the sub-technique of data staged for exfiltration through memory scraping. The attacker does not need to execute arbitrary code but rather relies on the victim's interaction with a crafted file that triggers the parsing logic within Word. This makes social engineering or phishing campaigns effective delivery mechanisms for exploiting this flaw in enterprise environments where users frequently open documents from external sources.
Mitigation strategies must focus on both technical controls and user awareness. Organizations should ensure that Microsoft Office applications are updated to the latest versions containing patches for this specific vulnerability, as Microsoft typically releases security updates addressing such memory safety issues through its monthly Patch Tuesday cycle or out-of-band updates if deemed critical. Additionally, implementing application control policies can restrict Word from processing documents originating from untrusted locations or block auto-play features that automatically render document previews without user interaction. Users should be trained to verify the source of any received documents and avoid opening files with unexpected extensions or those sent by unknown entities. Network monitoring tools may also detect anomalous memory access patterns if integrated with endpoint detection systems, although prevention at the application level remains the most effective defense against this class of vulnerability.