---
id: CVE-2026-64918
title: >-
  Insufficiently protected credentials in Microsoft Office allows an
  unauthorized attacker to perform spoofing over a network.
summary: >-
  Insufficiently protected credentials in Microsoft Office allows an
  unauthorized attacker to perform spoofing over a network.
severity: medium
cvss: 6.5
cvssVector: 'CVSS:3.1/AV:N/AC:L/PR:N/UI:R/S:U/C:H/I:N/A:N'
cwe:
  - CWE-522
vendor: microsoft
product: 365_apps
affected:
  - 365_apps
  - office_2016
  - office_2019
  - office_2021
  - office_2024
published: '2026-09-08'
updated: '2026-09-09'
sourceUpdated: '2026-09-09T18:11:14.393'
source: NVD
sourceUrl: 'https://nvd.nist.gov/vuln/detail/CVE-2026-64918'
references:
  - url: 'https://msrc.microsoft.com/update-guide/vulnerability/CVE-2026-64918'
    label: secure@microsoft.com
tags:
  - nvd
  - cve.org
ssvc:
  exploitation: none
  automatable: 'no'
  technicalImpact: partial
  timestamp: '2026-09-09T15:14:15.310825Z'
epss: 0.00477
epssPercentile: 0.40352
ingestedAt: '2026-09-08T19:08:49.604Z'
---

## Overview

Insufficiently protected credentials in Microsoft Office allows an unauthorized attacker to perform spoofing over a network.

## Affected

- `365_apps`
- `office_2016`
- `office_2019`
- `office_2021`
- `office_2024`

## Remediation

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