---
id: CVE-2026-45459
title: Microsoft Excel Security Feature Bypass Vulnerability
summary: >-
  Protection mechanism failure in Microsoft Office Excel allows an unauthorized
  attacker to bypass a security feature locally.
severity: low
cvss: 3.3
cvssVector: 'CVSS:3.1/AV:L/AC:L/PR:N/UI:R/S:U/C:L/I:N/A:N/E:U/RL:O/RC:C'
cvssSource: cna
cwe:
  - CWE-693
vendor: Microsoft
product: Microsoft 365 Apps for Enterprise
affected:
  - '365_apps_for_enterprise >= 16.0.1 < https://aka.ms/OfficeSecurityReleases'
  - office_365_for_mac >= 1.0.0 < 16.110.26061317
  - 'office_ltsc_2024 >= 16.0.0 < https://aka.ms/OfficeSecurityReleases'
  - office_ltsc_for_mac_2021 >= 16.0.1 < 16.110.26061317
  - office_ltsc_for_mac_2024 >= 16.0.0 < 16.110.26061317
ssvc:
  exploitation: none
  automatable: 'no'
  technicalImpact: partial
  timestamp: '2026-06-10T14:22:49.681713Z'
published: '2026-06-09'
updated: '2026-09-24'
sourceUpdated: '2026-09-24T13:44:21.119Z'
source: CVEORG
sourceUrl: 'https://www.cve.org/CVERecord?id=CVE-2026-45459'
references:
  - url: 'https://msrc.microsoft.com/update-guide/vulnerability/CVE-2026-45459'
    label: Microsoft Excel Security Feature Bypass Vulnerability
tags:
  - cve.org
epss: 0.00371
epssPercentile: 0.31029
ingestedAt: '2026-09-24T14:44:21.402Z'
---

## Overview

Protection mechanism failure in Microsoft Office Excel allows an unauthorized attacker to bypass a security feature locally.

## Affected

- `365_apps_for_enterprise >= 16.0.1 < https://aka.ms/OfficeSecurityReleases`
- `office_365_for_mac >= 1.0.0 < 16.110.26061317`
- `office_ltsc_2024 >= 16.0.0 < https://aka.ms/OfficeSecurityReleases`
- `office_ltsc_for_mac_2021 >= 16.0.1 < 16.110.26061317`
- `office_ltsc_for_mac_2024 >= 16.0.0 < 16.110.26061317`

## Remediation

Refer to the linked advisories for vendor-supplied fixes and affected version ranges.