Microsoft Office Excel Remote Code Execution Vulnerability
Summary
Use after free in Microsoft Office Excel allows an unauthorized attacker to execute code over a network. Published in October 2026 Security Updates. MSRC exploitability: Publicly Disclosed:No;Exploited:No;Latest Software Release:Exploitation Less Likely.
Why it matters
Microsoft published this item through its Security Update Guide, making it part of Patch Tuesday triage for affected Windows, cloud, or application estates. EPSS percentile: 55%.
Operator check
Review the Microsoft Security Update Guide entry for CVE-2026-100212. Confirm whether Microsoft Office Excel is deployed, then apply the current security update or documented mitigation. CVSS score: 8.8. EPSS probability: 0.8%; percentile: 55%.
Sources
PatchBrief uses public sources. It does not scan environments, verify exposure, or replace vendor guidance.