CVE-2026-56155

Published: Jul 14, 2026Modified: Jul 15, 2026CISA KEV

7.8

Vector

CVSS:3.1/AV:L/AC:L/PR:L/UI:N/S:U/C:H/I:H/A:H

Exploitability: 1.8 / Impact: 5.9

Source: secure@microsoft.com (Secondary)

Description

Insufficient granularity of access control in Active Directory Federation Services (AD FS) allows an authorized attacker to elevate privileges locally.

Affected (10)

Products: Microsoft: Windows 10 1607, Windows 10 1809, Windows Server 2012, Windows Server 2016, Windows Server 2019, Windows Server 2022, Windows Server 2025

7 products

Configuration A

10 vulnerable

Vulnerable Software	Affected Versions
Microsoft Windows 10 1607	Before 10.0.14393.9339
Microsoft Windows 10 1607	Before 10.0.14393.9339
Microsoft Windows 10 1809	Before 10.0.17763.9020
Microsoft Windows 10 1809	Before 10.0.17763.9020
Microsoft Windows Server 2012	All versions
Microsoft Windows Server 2012	Version r2
Microsoft Windows Server 2016	Before 10.0.14393.9339
Microsoft Windows Server 2019	Before 10.0.17763.9020
Microsoft Windows Server 2022	Before 10.0.20348.5386
Microsoft Windows Server 2025	Before 10.0.26100.33158

Related CWEs

CWE-1220

Insufficient Granularity of Access Control

The product implements access controls via a policy or other feature with the intention to disable or restrict accesses (reads and/or writes) to assets in a system from untrusted agents. However, implemented access controls lack required granularity, which renders the control policy too broad because it allows accesses from unauthorized agents to the security-sensitive assets.

References (2)

https://msrc.microsoft.com/update-guide/vulnerability/CVE-2026-56155

Source: secure@microsoft.com

Vendor Advisory

https://www.cisa.gov/known-exploited-vulnerabilities-catalog?field_cve=CVE-2026-56155

Source: 134c704f-9b21-4f2e-91b3-4a467353bcc0

US Government Resource

Timeline

No history available yet.