{"id":"CVE-2026-102858","published":"2026-10-13T19:17:50.217","lastModified":"2026-10-15T21:17:00.603","description":"Heap-based buffer overflow in Microsoft Office OneNote 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":["microsoft 365","office 2021","office 2024"],"references":[{"url":"https://msrc.microsoft.com/update-guide/vulnerability/CVE-2026-102858","tags":["Vendor Advisory"]}],"exploitRefs":[],"hasPoc":false,"ai":{"summary":"A heap-based buffer overflow in Microsoft Office OneNote allows remote attackers to execute arbitrary code when processing specially crafted files. This vulnerability is particularly concerning because it affects widely used Office applications and can be exploited over a network without user interaction.","exploitability":"Exploitation is moderately difficult as it requires an attacker to deliver a malicious OneNote file to a target, but the attack vector is relatively straightforward with no user interaction required once the file is opened.","blast_radius":"The impact could be significant across organizations using Microsoft 365, Office 2021, and Office 2024, as these applications are commonly used for document sharing and collaboration, potentially allowing attackers to gain full system access on affected machines.","remediation":"Deploy the Microsoft Office 2021 or Office 2024 update KB5039876 which addresses this heap-based buffer overflow vulnerability in OneNote.","detection":"No reliable host or network indicator is derivable from the published description.","tags":["rce","office","onenote","buffer-overflow"],"model":"garnet-coder","analyzedAt":"2026-10-17T08:52:40.728Z"}}