CVE-2026-56155 Microsoft Active Directory Federation Services Insufficient Granularity of Access Control Vulnerability
An authorized attacker can elevate privileges locally due to insufficient access control granularity in Active Directory Federation Services.
- Exploited in the wild
- Since 14 Jul 2026
- Login needed
- Any signed-in user
- Attackable
- Local or same network only
- Victim action needed
- Not needed
- Fix
- None listed
What is CVE-2026-56155?
CVE-2026-56155 is a high-severity vulnerability in Microsoft Windows 10 1607, published on 14 Jul 2026. It can only be exploited from the same machine or local network, with no action from the victim.
Official description
Insufficient granularity of access control in Active Directory Federation Services (AD FS) allows an authorized attacker to elevate privileges locally.
Weakness: CWE-1220
Which versions are affected by CVE-2026-56155?
It affects 7 products.
Products include Microsoft Windows 10 1607, Microsoft Windows 10 1809, Microsoft Windows Server 2012, Microsoft Windows Server 2016, Microsoft Windows Server 2019, Microsoft Windows Server 2022 and 1 more.
How do I fix CVE-2026-56155?
No fix has been published for CVE-2026-56155 yet. Limit exposure of the affected software until one is available. US federal agencies must fix it by 28 Jul 2026.
Is CVE-2026-56155 being exploited?
Yes. Attackers have exploited CVE-2026-56155 in the wild since at least 14 Jul 2026.
Other vulnerabilities in Microsoft Windows 10 1607
- CVE-2026-33824 Microsoft Internet Key Exchange (IKE) Service Extensions Double Free
- CVE-2026-21510 Microsoft Windows Shell Protection Mechanism Failure
- CVE-2026-21513 Microsoft MSHTML Framework Protection Mechanism Failure
- CVE-2023-32049 Microsoft Windows Defender SmartScreen Security Feature Bypass
- CVE-2023-29360 Microsoft Streaming Service Untrusted Pointer Dereference
Sources
Also known as GHSA-p436-qch3-9m59.