---
id: CVE-2026-97778
title: >-
  Integer overflow or wraparound in Microsoft Office Excel allows an
  unauthorized attacker to execute code over a network.
summary: >-
  Integer overflow or wraparound in Microsoft Office Excel allows an
  unauthorized attacker to execute code over a network.
severity: high
cvss: 8.8
cvssVector: 'CVSS:3.1/AV:N/AC:L/PR:N/UI:R/S:U/C:H/I:H/A:H'
cwe:
  - CWE-190
vendor: microsoft
product: 365_apps
affected:
  - 365_apps
  - microsoft_365
  - office_2021
  - office_2024
  - office_online_server < 16.0.10417.20228
patched:
  - office_online_server 16.0.10417.20228
published: '2026-10-13'
updated: '2026-10-14'
sourceUpdated: '2026-10-14T20:06:28.530'
source: NVD
sourceUrl: 'https://nvd.nist.gov/vuln/detail/CVE-2026-97778'
references:
  - url: 'https://msrc.microsoft.com/update-guide/vulnerability/CVE-2026-97778'
    label: secure@microsoft.com
tags:
  - nvd
  - cve.org
epss: 0.00601
epssPercentile: 0.47534
ingestedAt: '2026-10-13T19:43:29.303Z'
ssvc:
  exploitation: none
  automatable: 'no'
  technicalImpact: total
  timestamp: '2026-10-13T19:32:20.342443Z'
---

## Overview

Integer overflow or wraparound in Microsoft Office Excel allows an unauthorized attacker to execute code over a network.

## Affected

- `365_apps`
- `microsoft_365`
- `office_2021`
- `office_2024`
- `office_online_server < 16.0.10417.20228`

## Remediation

Upgrade past the affected range:

- `office_online_server 16.0.10417.20228`