CVE-2026-55050 in Office
Summary
by MITRE • 07/14/2026
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 • 07/15/2026
This vulnerability represents a critical out-of-bounds read flaw in Microsoft Office Word that enables unauthorized attackers to potentially access sensitive local information through crafted malicious documents. The technical nature of this vulnerability stems from insufficient input validation and memory management within the word processing application's document parsing routines. When Word processes specially crafted Office documents containing malformed data structures, it fails to properly bounds-check array accesses or buffer operations, leading to memory read operations that extend beyond allocated memory boundaries.
The operational impact of this vulnerability extends beyond simple information disclosure as it provides attackers with a potential foothold for more sophisticated attacks within the target system. An attacker could leverage this flaw to extract sensitive data from memory locations that should remain protected, potentially including credentials, personal information, or other confidential data stored in adjacent memory regions. The attack typically requires social engineering to deliver malicious documents to unsuspecting users who then open them with Word applications, making this a prevalent vector for targeted attacks against corporate networks and individual users.
From a cybersecurity perspective, this vulnerability aligns with CWE-129 which defines improper validation of array index bounds, and can be categorized under ATT&CK technique T1059.005 for command and scripting interpreter usage in Windows environments. The flaw represents a classic memory safety issue that has plagued software applications for decades, particularly affecting document processing applications that must handle complex file formats with extensive data structures. Microsoft's vulnerability classification indicates this affects multiple versions of Word across different operating systems, making it a widespread concern for enterprise security teams.
Mitigation strategies should include immediate deployment of Microsoft's security patches and updates to address the underlying memory handling issues in Word's document parsing engine. Organizations should implement comprehensive email filtering solutions to detect potentially malicious Office documents before they reach end users, while also establishing strict document approval workflows for sensitive environments. Network segmentation and privilege separation can limit the potential damage if exploitation occurs, though these measures do not prevent the initial information disclosure attack vector. Security awareness training remains crucial for end users to recognize suspicious email attachments and avoid opening untrusted Office documents that could exploit this vulnerability.