CVE-2026-70314 in Office
Summary
by MITRE • 08/12/2026
Improper input validation in Microsoft Office 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 weakness in Microsoft Office's input validation mechanisms that enables unauthorized attackers to achieve local information disclosure. The flaw occurs when the application fails to properly validate user-supplied data during processing of various file formats, creating opportunities for malicious actors to exploit the system through crafted inputs. This type of vulnerability typically falls under CWE-20, which addresses improper input validation as a fundamental security weakness that can lead to various downstream attacks including information disclosure, privilege escalation, and arbitrary code execution.
The technical implementation of this vulnerability involves Microsoft Office applications processing files with malformed or maliciously constructed data structures that bypass normal validation checks. When these applications encounter such inputs, they may inadvertently expose internal system information, memory contents, or configuration details through error messages, crash dumps, or other diagnostic outputs. The exploitation often requires the victim to open a specially crafted document or file that triggers the vulnerable code path within the Office application. Attackers can leverage this weakness to gather intelligence about the target system including installed software versions, system configurations, and potentially sensitive data stored locally.
From an operational perspective, this vulnerability presents significant risks in enterprise environments where Microsoft Office remains the primary productivity suite. The attack vector typically involves social engineering campaigns where users are tricked into opening malicious documents through email attachments or compromised websites. Once executed, the local information disclosure can provide attackers with valuable reconnaissance data to plan more sophisticated attacks against the system or network infrastructure. The impact extends beyond simple information leakage as this initial foothold can enable further exploitation attempts including privilege escalation and lateral movement within the organization's network.
Organizations should implement multiple layers of defense to mitigate this vulnerability effectively. Immediate remediation involves applying Microsoft's security patches and updates as soon as they become available through regular Windows Update processes or direct download from Microsoft's security center. Additionally, implementing strict file validation policies within email gateways and web proxies can prevent malicious documents from reaching end users. Network segmentation and privilege separation practices help limit the potential damage if exploitation occurs. Security awareness training programs should emphasize the dangers of opening unexpected attachments and visiting untrusted websites. Organizations should also consider deploying application whitelisting solutions to restrict execution of unauthorized Office macros or potentially malicious file formats. The vulnerability demonstrates the importance of defense-in-depth strategies as outlined in nist cybersecurity framework and aligns with attack techniques categorized under mitre att&ck tactic initial access and privilege escalation.