AI analysis
CVE-2026-97761 is a stack-based buffer overflow (CWE-121) in Microsoft Office Excel. An unauthorized attacker can trigger it over a network by getting a user to open or otherwise interact with malicious content; no prior privileges are required, but user interaction is required. Successful exploitation allows remote code execution with high impact on confidentiality, integrity, and availability (CVSS 3.1 8.8). Microsoft 365, Microsoft 365 Apps, Office 2021, and Office 2024 are the affected products named in the data. It is not listed in CISA KEV, no public proof-of-concept is known, and it was called out among prominent issues in October 2026 Patch Tuesday coverage.
What to do: Apply Microsoft's October 2026 security updates for Excel in Microsoft 365, Microsoft 365 Apps, Office 2021, and Office 2024 as soon as they are offered. Until those updates are installed, do not open unsolicited or unexpected Excel files, and restrict macros and active content from untrusted sources. No public exploit is known, but the issue needs only user interaction, so prioritize widely used desktops and shared workstations.
Affected
| Microsoft 365 Apps | — |
| Microsoft 365 | — |
| Microsoft Office 2021 | — |
| Microsoft Office 2024 | — |
Estimated exposure
massOn the order of hundreds of millions of Office/Microsoft 365 users with Excel — Microsoft 365 and perpetual Office (including Excel in Office 2021 and Office 2024) are among the most widely deployed productivity suites; published commercial-seat and consumer figures put the global install base in the hundreds of…
Order-of-magnitude estimate by the model from install counts, market share and public scan data it knows; verify before quoting.