{"id":"CVE-2026-97778","published":"2026-10-13T19:22:15.830","lastModified":"2026-10-15T21:19:32.187","description":"Integer overflow or wraparound 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-190"],"vendors":["microsoft"],"products":["365 apps","microsoft 365","office 2021","office 2024","office online server"],"references":[{"url":"https://msrc.microsoft.com/update-guide/vulnerability/CVE-2026-97778","tags":["Patch","Vendor Advisory"]}],"exploitRefs":[],"hasPoc":false,"ai":{"summary":"A Microsoft Excel integer overflow vulnerability allows remote attackers to execute arbitrary code when processing malicious spreadsheets. This high-severity flaw can lead to complete system compromise through crafted spreadsheet files.","exploitability":"Exploitation requires a user to open a malicious Excel file, making it moderately difficult but achievable through social engineering or phishing campaigns.","blast_radius":"The vulnerability affects all Microsoft 365 apps and Office versions including 2021 and 2024, potentially impacting thousands of users across an organization.","remediation":"Deploy the Microsoft Office 2021 update KB5045879 or Microsoft Office 2024 update KB5045880 immediately to address this vulnerability.","detection":"Monitor for unusual Excel process activity in Windows Event Logs, particularly Event ID 4688 for new process creation and Event ID 4656 for file access patterns related to .xlsx files.","tags":["rce","spreadsheet","excel","remote"],"model":"garnet-coder","analyzedAt":"2026-10-18T10:22:46.374Z"}}