CVE-2026-63517 in Office
Summary
by MITRE • 08/11/2026
Out-of-bounds read in Microsoft Office allows an unauthorized attacker to disclose information locally.
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Analysis
by VulDB Data Team • 08/11/2026
This vulnerability represents a critical out-of-bounds read flaw within Microsoft Office applications that enables unauthorized attackers to extract sensitive information from the local system. The technical implementation involves memory access violations where the office application fails to properly validate array bounds during document processing operations, allowing malicious actors to read data beyond allocated memory regions. Such flaws typically occur when input validation mechanisms are insufficient or absent, creating opportunities for attackers to manipulate document structures and trigger unintended memory reads.
The operational impact of this vulnerability extends beyond simple information disclosure, as it can potentially expose sensitive data including user credentials, system configuration details, or proprietary business information stored in memory buffers. Attackers can leverage this weakness through maliciously crafted office documents delivered via email attachments, file sharing platforms, or compromised websites, making it particularly dangerous in enterprise environments where document processing is common. The vulnerability aligns with CWE-129 which specifically addresses improper validation of length of input buffers, and represents a classic example of memory safety issues that have plagued software applications for decades.
According to ATT&CK framework, this vulnerability maps to technique T1059.005 for execution through office applications, and T1005 for data collection through information discovery mechanisms. The attack vector typically involves social engineering campaigns where users are诱导ed to open malicious documents that trigger the out-of-bounds read condition, potentially leading to further exploitation or lateral movement within compromised networks. Organizations should implement comprehensive patch management strategies targeting Microsoft Office updates, deploy application whitelisting policies to restrict execution of untrusted documents, and configure email security solutions to filter suspicious office document attachments.
Mitigation approaches must include immediate deployment of Microsoft security patches addressing the specific memory validation issues, combined with network segmentation controls to limit potential lateral movement if exploitation occurs. Security teams should also establish monitoring protocols to detect unusual document processing patterns that might indicate exploitation attempts. Additionally implementing principle of least privilege access controls and regular security awareness training for users can significantly reduce the risk of successful exploitation through this vulnerability class. The remediation process requires coordination between IT operations, security teams, and end-user support to ensure comprehensive coverage across all office application environments while maintaining business continuity requirements.