CVE-2026-55022 in Office
Summary
by MITRE • 07/14/2026
Access of resource using incompatible type ('type confusion') in Microsoft Office allows an unauthorized attacker to execute code locally.
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Analysis
by VulDB Data Team • 07/14/2026
Type confusion vulnerabilities represent a critical class of software flaws that occur when a program uses a resource with an inappropriate data type, often leading to memory corruption and potential remote code execution. This specific vulnerability exists within Microsoft Office applications where improper type handling allows attackers to manipulate object references and execute arbitrary code on affected systems. The flaw typically manifests when the application processes untrusted input through functions that do not properly validate or enforce type constraints during object manipulation phases.
Microsoft Office products are widely used across enterprise environments, making this vulnerability particularly dangerous as it can be exploited through various attack vectors including malicious email attachments, compromised websites, or documents shared via collaboration platforms. The type confusion occurs at runtime when the application's memory management system encounters objects that are expected to be of one type but are actually of another, creating opportunities for attackers to craft malicious input that triggers unintended code paths. This vulnerability aligns with CWE-466 which specifically addresses the use of an incorrect data type for a resource, and falls under the broader category of memory safety issues that have historically led to numerous exploitation techniques.
The operational impact of this vulnerability extends beyond simple privilege escalation as attackers can leverage it to gain full control over affected systems. Once executed, malicious code can establish persistence mechanisms, exfiltrate sensitive data, or serve as a staging ground for further attacks within the network infrastructure. The attack surface is particularly broad given that Office applications are frequently used for document processing across different user roles and security boundaries. Organizations may experience significant disruption when these vulnerabilities are exploited, potentially leading to data breaches, system compromise, and regulatory compliance violations.
Mitigation strategies should focus on immediate patch management across all affected Microsoft Office versions while implementing additional defensive measures such as application control policies, email filtering solutions, and network segmentation to limit lateral movement. Security teams should also consider deploying exploit prevention technologies that monitor for suspicious memory access patterns and type-related anomalies. Regular security awareness training for end users can help reduce the risk of successful exploitation through social engineering vectors, while maintaining up-to-date threat intelligence feeds enables organizations to detect and respond to emerging threats targeting these vulnerabilities. The ATT&CK framework categorizes such exploits under T1059 for command and scripting interpreter and T1203 for Exploitation for Client Execution, highlighting the need for comprehensive defensive measures across multiple attack phases.