CVE-2026-54130

CRITICAL

M365 Copilot Information Disclosure Vulnerability

Title source: cna
STIX 2.1

Description

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

References (1)

Core 1
Core References
Vendor Advisory vendor-advisory patch
M365 Copilot Information Disclosure Vulnerability
https://msrc.microsoft.com/update-guide/vulnerability/CVE-2026-54130

Scores

CVSS v3 9.8
EPSS 0.0058
EPSS Percentile 43.6%
Attack Vector NETWORK
CVSS:3.1/AV:N/AC:L/PR:N/UI:N/S:U/C:H/I:H/A:H

CISA SSVC

Vulnrichment
Exploitation none
Automatable no
Technical Impact total

Details

CWE
CWE-306
Status published
Products (2)
microsoft/365_copilot
Microsoft/Microsoft 365 Copilot -
Published Jun 18, 2026
Tracked Since Jun 19, 2026