SOC status:Duty analyst on shift

UK Cyber Defence
VulnerabilityAnalyzed

CVE-2026-54130

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

HIGH 7.5EPSS 1.08%

Does this matter?

High impact if exploited, but EPSS currently rates exploitation as unlikely (1.08%). Schedule it in the normal patch cycle and watch for a rise in EPSS or a public exploit.

Description

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

CVSS 3.1
7.5 HIGHCVSS:3.1/AV:N/AC:L/PR:N/UI:N/S:U/C:H/I:N/A:N
EPSS
1.08% probability · 63th percentile
CISA KEV
Not listed
Weakness
CWE-306
Affected
microsoft/365 copilot
Source
secure@microsoft.com

Source: NVD record, EPSS from FIRST.org, KEV from CISA. Refreshed daily.