CVE-2026-70310 in Office
Summary
by MITRE • 08/12/2026
Out-of-bounds read in Microsoft Office Word allows an unauthorized attacker to disclose information locally.
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Analysis
by VulDB Data Team • 08/12/2026
This vulnerability represents a critical out-of-bounds read flaw within Microsoft Office Word that enables unauthorized attackers to extract sensitive information from the target system. The technical implementation involves memory access violations where the application fails to properly validate array indices or buffer boundaries during document processing operations. When Word encounters malformed or specially crafted document content, it attempts to read memory locations beyond the allocated buffer space, potentially exposing confidential data stored in adjacent memory regions including credentials, encryption keys, or other sensitive system information.
The operational impact of this vulnerability extends beyond simple information disclosure as it provides attackers with a foothold for further exploitation within local environments. Attackers can leverage this flaw through various delivery vectors including malicious email attachments, compromised websites, or social engineering campaigns targeting Word document consumption. The vulnerability operates at the application level and requires minimal privileges to exploit, making it particularly dangerous in enterprise environments where Office applications are frequently used. The out-of-bounds read condition typically occurs during document parsing operations when processing malformed structured data formats such as xml or binary office document components.
From a cybersecurity perspective, this vulnerability aligns with common weakness enumeration CWE-129 and represents a specific instance of improper input validation that enables memory safety issues. The attack pattern corresponds to techniques described in the attack tree framework under software exploitation categories where memory corruption vulnerabilities serve as entry points for privilege escalation or information theft operations. Organizations running vulnerable versions of Microsoft Office Word face significant risk exposure as this flaw can be exploited without user interaction when documents are opened, making it particularly dangerous in automated threat scenarios.
The recommended mitigation strategies include immediate deployment of Microsoft security updates and patches addressing the specific memory validation issues within Word's document parsing engine. System administrators should implement application whitelisting policies to restrict execution of untrusted Office documents and consider enabling enhanced security features such as Windows Defender Application Control or similar sandboxing technologies. Network segmentation and monitoring solutions should be configured to detect suspicious document handling activities, while user education programs can help reduce successful exploitation through awareness of phishing and social engineering threats targeting office productivity applications. Additionally, regular vulnerability assessments and penetration testing should verify the effectiveness of implemented controls against this specific class of memory safety issues.