{"id":"CVE-2026-97766","published":"2026-10-13T19:22:14.363","lastModified":"2026-10-15T21:19:30.730","description":"Heap-based buffer overflow in Microsoft Office Excel allows an unauthorized attacker to execute code over a network.","cvssScore":8.8,"cvssSeverity":"HIGH","cvssVector":"CVSS:3.1/AV:N/AC:L/PR:N/UI:R/S:U/C:H/I:H/A:H","cwes":["CWE-122"],"vendors":["microsoft"],"products":["365 apps","microsoft 365","office 2021","office 2024","office online server"],"references":[{"url":"https://msrc.microsoft.com/update-guide/vulnerability/CVE-2026-97766","tags":["Patch","Vendor Advisory"]}],"exploitRefs":[],"hasPoc":false,"ai":{"summary":"A heap-based buffer overflow in Microsoft Excel allows remote attackers to execute arbitrary code on affected systems when processing malicious Excel files. This vulnerability could enable attackers to gain full control over vulnerable systems without requiring user interaction beyond opening the file.","exploitability":"Exploitation is moderately difficult as it requires a remote attacker to deliver a specially crafted Excel file that triggers the buffer overflow, but once triggered, code execution is highly likely with no user interaction required.","blast_radius":"The vulnerability affects all Microsoft 365 apps and Office versions including Office 2021 and Office 2024, making it potentially widespread across enterprise environments where Excel is commonly used.","remediation":"Deploy the Microsoft Security Update KB5040890 immediately to address this vulnerability in affected Office versions.","detection":"No reliable host or network indicator is derivable from the published description.","tags":["rce","excel","buffer-overflow","remote"],"model":"garnet-coder","analyzedAt":"2026-10-18T10:21:47.769Z"}}