CVE-2026-83666: Active Directory Certificate Services (AD CS) Elevation of Privilege Vulnerability
Active Directory Certificate Services (AD CS) Elevation of Privilege Vulnerability
Other sources
Concurrent execution using shared resource with improper synchronization ('race condition') in Active Directory Certificate Services (AD CS) allows an authorized attacker to elevate privileges locally.
— Microsoft
Affected Software
Remediation
Recommended actions to resolve this vulnerability, in priority order.
- Upgrade
Upgrade to a fixed release to a version that resolves this vulnerability.
Fixed in 10.0.14393.9612Patch KB5126868 - Upgrade
Upgrade to a fixed release to a version that resolves this vulnerability.
Fixed in 6.2.9200.26434Patch KB5126835 - Upgrade
Upgrade to a fixed release to a version that resolves this vulnerability.
Fixed in 10.0.26100.33650Patch KB5126646 - Upgrade
Upgrade to a fixed release to a version that resolves this vulnerability.
Fixed in 6.3.9600.23470Patch KB5126836 - Upgrade
Upgrade to a fixed release to a version that resolves this vulnerability.
Fixed in 10.0.20348.5761Patch KB5126655 - Upgrade
Upgrade to a fixed release to a version that resolves this vulnerability.
Fixed in 10.0.17763.9376Patch KB5126651
Event History
Frequently Asked Questions
Who is realistically exposed to this issue?
Systems running the listed Windows client or server products are in scope where Active Directory Certificate Services is present. Exploitation is local, so the primary concern is a user or process that already has authorized access to the affected system.
What does an attacker need to exploit it?
The attacker must be authorized and able to execute locally on the affected system. Exploitation also has high attack complexity because it relies on a race condition involving concurrent use of a shared resource; no user interaction is required.
What is the likely impact if exploitation succeeds?
A successful attacker can elevate privileges locally. The supplied vector indicates high potential impact to confidentiality, integrity, and availability.