VulnerabilityAnalyzed
CVE-2026-54121
Improper authorization in Active Directory Certificate Services (AD CS) allows an authorized attacker to elevate privileges over a network.
HIGH 8.8EPSS 1.79%
Does this matter?
High impact if exploited, but EPSS currently rates exploitation as unlikely (1.79%). Schedule it in the normal patch cycle and watch for a rise in EPSS or a public exploit.
Description
Improper authorization in Active Directory Certificate Services (AD CS) allows an authorized attacker to elevate privileges over a network.
- CVSS 3.1
- 8.8 HIGHCVSS:3.1/AV:N/AC:L/PR:L/UI:N/S:U/C:H/I:H/A:H
- EPSS
- 1.79% probability · 77th percentile
- CISA KEV
- Not listed
- Weakness
- CWE-285
- Affected
- microsoft/windows 10 1607 · microsoft/windows 10 1809 · microsoft/windows server 2012 · microsoft/windows server 2016 · microsoft/windows server 2019 · microsoft/windows server 2022 · microsoft/windows server 2025
- Source
- secure@microsoft.com
References
- https://msrc.microsoft.com/update-guide/vulnerability/CVE-2026-54121Patch, Vendor Advisory
Source: NVD record, EPSS from FIRST.org, KEV from CISA. Refreshed daily.