---
id: CVE-2026-54130
title: M365 Copilot Information Disclosure Vulnerability
summary: >-
  Missing authentication for critical function in M365 Copilot allows an
  unauthorized attacker to disclose information over a network.
severity: critical
cvss: 9.8
cvssVector: 'CVSS:3.1/AV:N/AC:L/PR:N/UI:N/S:U/C:H/I:H/A:H/E:U/RL:O/RC:C'
cvssSource: cna
cwe:
  - CWE-306
vendor: Microsoft
product: Microsoft 365 Copilot
affected:
  - 365_copilot -
ssvc:
  exploitation: none
  automatable: 'no'
  technicalImpact: total
  timestamp: '2026-06-23T00:00:00+00:00'
published: '2026-06-18'
updated: '2026-09-24'
sourceUpdated: '2026-09-24T13:43:32.796Z'
source: CVEORG
sourceUrl: 'https://www.cve.org/CVERecord?id=CVE-2026-54130'
references:
  - url: 'https://msrc.microsoft.com/update-guide/vulnerability/CVE-2026-54130'
    label: M365 Copilot Information Disclosure Vulnerability
tags:
  - cve.org
epss: 0.01084
epssPercentile: 0.63749
ingestedAt: '2026-09-24T14:44:21.436Z'
---

## Overview

Missing authentication for critical function in M365 Copilot allows an unauthorized attacker to disclose information over a network.

## Affected

- `365_copilot -`

## Remediation

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