CVE-2026-55023 in Office
Summary
by MITRE • 07/14/2026
Out-of-bounds read in Microsoft Office allows an unauthorized attacker to disclose information locally.
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Analysis
by VulDB Data Team • 07/14/2026
This vulnerability represents a critical out-of-bounds read flaw within Microsoft Office applications that enables unauthorized attackers to extract sensitive information from the local system. The technical nature of this vulnerability stems from improper input validation and memory management practices within the office suite's processing components, particularly affecting document parsing and rendering functionalities. When Microsoft Office encounters malformed or maliciously crafted documents, the application fails to properly bounds-check array accesses or memory operations, allowing attackers to read data from adjacent memory locations beyond intended boundaries. This type of vulnerability falls under the common weakness enumeration CWE-125 which specifically addresses out-of-bounds read conditions in software applications. The operational impact of this flaw extends beyond simple information disclosure as it can potentially expose sensitive data such as encryption keys, user credentials, system configuration details, or other confidential information stored in adjacent memory segments. Attackers can exploit this vulnerability by crafting specially designed office documents that trigger the out-of-bounds read condition when opened or processed by vulnerable applications, making it particularly dangerous in phishing campaigns or targeted attacks where document-based exploitation is common. The attack vector aligns with techniques described in the attack pattern taxonomy under ATT&CK tactic TA0001 (Initial Access) and technique T1204.002 (User Execution), as successful exploitation typically requires user interaction with malicious documents. From a security perspective, this vulnerability demonstrates the critical importance of robust memory safety practices and input validation in enterprise software applications. The flaw represents a significant risk to organizations as it can be exploited through various attack scenarios including social engineering campaigns where users are tricked into opening malicious office documents. Microsoft typically addresses such vulnerabilities through regular security updates and patches that implement proper bounds checking mechanisms, improved memory management routines, and enhanced input sanitization processes. Organizations should prioritize immediate patch deployment and implement additional security controls such as email filtering, application whitelisting, and user awareness training to mitigate the risk associated with this class of vulnerability. The exploitation of out-of-bounds read conditions like this one often requires minimal privileges and can be particularly dangerous when combined with other attack techniques or when targeting high-value systems within enterprise environments. This vulnerability type also highlights the ongoing challenges in developing secure software systems where memory safety issues continue to represent persistent threats despite advances in programming languages and development practices. Security professionals should monitor for indicators of compromise related to this vulnerability through network traffic analysis, endpoint detection and response monitoring, and system log reviews to identify potential exploitation attempts and ensure comprehensive protection against such attacks.