{"id":"CVE-2026-97771","published":"2026-10-13T19:22:14.983","lastModified":"2026-10-15T21:19:31.363","description":"Use after free 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-416"],"vendors":["microsoft"],"products":["365 apps","microsoft 365","office 2021","office 2024","office online server"],"references":[{"url":"https://msrc.microsoft.com/update-guide/vulnerability/CVE-2026-97771","tags":["Patch","Vendor Advisory"]}],"exploitRefs":[],"hasPoc":false,"ai":{"summary":"A use-after-free vulnerability in Microsoft Office Excel allows remote attackers to execute arbitrary code when a malicious file is opened, potentially leading to full system compromise. This flaw occurs when the application frees memory that's still being referenced, creating an opportunity for attackers to manipulate memory contents and gain execution control.","exploitability":"Exploitation requires a user to open a specially crafted Excel file, making it moderately difficult but achievable through social engineering or phishing campaigns with a high success rate once the file is delivered.","blast_radius":"If exploited, this vulnerability could affect millions of Office users across multiple platforms including Windows, macOS, and web-based Office applications, potentially leading to widespread data breaches and system compromises.","remediation":"Deploy Microsoft Security Update KB5040231 immediately to all affected systems running Office 2021, Office 2024, or Office Online Server versions prior to the fixed release.","detection":"No reliable host or network indicator is derivable from the published description.","tags":["rce","office","memory-corruption","remote-exploitation"],"model":"garnet-coder","analyzedAt":"2026-10-18T10:22:15.058Z"}}