CVE-2026-63524 in Office
Summary
by MITRE • 08/11/2026
Out-of-bounds read in Microsoft Office allows an unauthorized attacker to disclose information locally.
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Analysis
by VulDB Data Team • 08/11/2026
This vulnerability represents a critical out-of-bounds read flaw in Microsoft Office applications that enables unauthorized attackers to extract sensitive information from the local system. The technical implementation involves improper bounds checking within the office document parsing mechanisms, where the application fails to validate array indices or memory access boundaries when processing maliciously crafted Office files. This allows an attacker to read memory locations beyond the intended buffer limits, potentially exposing confidential data such as credentials, encryption keys, or other sensitive information stored in adjacent memory regions.
The operational impact of this vulnerability extends beyond simple information disclosure, as it can serve as a foundational weakness for more sophisticated attacks within the attack chain. According to the ATT&CK framework, this vulnerability aligns with techniques involving privilege escalation and credential access through initial compromise vectors that leverage application vulnerabilities. The flaw typically manifests when users open maliciously crafted office documents, either through email attachments or web downloads, making it particularly dangerous in targeted phishing campaigns. The out-of-bounds read behavior can be exploited to disclose memory contents that may include stack canaries, heap metadata, or even sensitive data from other processes running on the same system.
From a cybersecurity perspective, this vulnerability exemplifies the common pattern of buffer overflow and memory corruption issues that have plagued office productivity suites for years. The underlying cause often stems from insufficient input validation and memory management practices within legacy codebases, where developers may not have properly implemented bounds checking or used safe programming constructs. Organizations implementing Microsoft Office products face significant risk exposure, as this vulnerability can be leveraged for reconnaissance purposes to gather system information that could aid in subsequent attack phases. The vulnerability's local nature means that exploitation typically requires user interaction with malicious content, but once triggered, it can provide attackers with access to data that should remain protected within the application's memory space.
Mitigation strategies must address both immediate defensive measures and long-term architectural improvements to prevent similar vulnerabilities from emerging in future releases. Organizations should implement strict email filtering policies to prevent delivery of potentially malicious Office documents, while also ensuring timely deployment of Microsoft security updates that address this specific out-of-bounds read issue. The CWE database categorizes this vulnerability under CWE-129 which specifically addresses insufficient validation of length of inputs, highlighting the fundamental design flaw in input handling mechanisms. Additionally, deploying application whitelisting solutions and implementing sandboxing techniques can significantly reduce the attack surface for exploitation attempts, while regular security assessments of office document processing libraries can help identify similar vulnerabilities before they are exploited in the wild.