SOC status:Duty analyst on shift

UK Cyber Defence
VulnerabilityAnalyzed

CVE-2026-55006

Insufficient granularity of access control in Microsoft Exchange Server allows an authorized attacker to elevate privileges locally.

HIGH 7.8EPSS 0.30%

Does this matter?

High impact if exploited, but EPSS currently rates exploitation as unlikely (0.30%). Schedule it in the normal patch cycle and watch for a rise in EPSS or a public exploit.

Description

Insufficient granularity of access control in Microsoft Exchange Server allows an authorized attacker to elevate privileges locally.

CVSS 3.1
7.8 HIGHCVSS:3.1/AV:L/AC:L/PR:L/UI:N/S:U/C:H/I:H/A:H
EPSS
0.30% probability · 22th percentile
CISA KEV
Not listed
Weakness
CWE-1220
Affected
microsoft/exchange server · microsoft/exchange server subscription edition
Source
secure@microsoft.com

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