CVE-2026-50314 in Office
Summary
by MITRE • 07/14/2026
Use after free in Microsoft Office allows an unauthorized attacker to execute code locally.
Statistical analysis made it clear that VulDB provides the best quality for vulnerability data.
Analysis
by VulDB Data Team • 07/14/2026
This vulnerability represents a critical use-after-free condition in Microsoft Office applications that enables remote code execution through maliciously crafted office documents. The flaw occurs when the application fails to properly manage memory references after an object has been freed, creating a scenario where subsequent operations can access already deallocated memory regions. This type of vulnerability falls under CWE-416 which specifically addresses use-after-free conditions in software applications. Attackers can exploit this weakness by crafting specially designed office files containing malicious payloads that trigger the vulnerable code path during document processing.
The technical implementation involves manipulation of memory management routines within Microsoft Office's document parsing engines, particularly affecting word processors and spreadsheet applications. When a user opens an infected document, the application processes the malformed data structure which leads to improper memory deallocation followed by subsequent access attempts to freed memory locations. This creates opportunities for attackers to inject and execute arbitrary code with the privileges of the targeted user account. The vulnerability is particularly dangerous because it can be triggered through routine document opening operations without requiring any special user interaction beyond opening the malicious file.
The operational impact of this vulnerability extends beyond simple privilege escalation as it provides attackers with persistent access to target systems through local code execution capabilities. Once successfully exploited, adversaries can establish backdoors, escalate privileges, and maintain long-term presence on compromised endpoints. This aligns with ATT&CK technique T1059 which covers command and scripting interpreter usage, and T1068 which addresses exploit for privilege escalation. The vulnerability affects multiple Microsoft Office products including Word, Excel, PowerPoint, and other document processing applications that share common memory management components.
Mitigation strategies should include immediate deployment of Microsoft security patches addressing the identified use-after-free condition, along with enhanced email filtering to prevent delivery of malicious office documents. Organizations should implement application whitelisting policies to restrict execution of untrusted Office files, while maintaining regular system updates to address similar vulnerabilities in the broader Microsoft Office ecosystem. Network segmentation and user access controls can help limit potential damage from successful exploitation attempts, though the most effective defense remains prompt patch deployment and comprehensive security awareness training for end users.