CVE-2026-56155Active Directory Federation Services Elevation of Privilege Vulnerability
Updated under an hour ago ()
Does this affect you?
It affects Microsoft Windows 10 Version 1607 and 7 other products. Add what you run to find out whether that includes you.
CISA lists it as known exploited since Jul 14, 2026; federal agencies had to remediate by Jul 28, 2026. Treat that date as your deadline.
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Insufficient granularity of access control in Active Directory Federation Services (AD FS) allows an authorized attacker to elevate privileges locally.
- CVSS
- 7.8 HIGH (v3.1, CNA)CVSS:3.1/AV:L/AC:L/PR:L/UI:N/S:U/C:H/I:H/A:H/E:F/RL:O/RC:C
- Weakness (CWE)
- CWE-1220
- Known exploited
- Added to CISA KEV Jul 14, 2026; federal remediation due Jul 28, 2026Apply mitigations in accordance with vendor instructions, ensuring compliance with CISA’s BOD 26-04 Prioritizing Security Updates Based on Risk (see URL in Notes) guidance and CISA’s “Forensics Triage Requirements” (see URL in Notes). Follow applicable BOD 26-04 guidance for cloud services or discontinue use of the product if mitigations are unavailable. Stakeholders are responsible for evaluating each asset's internet exposure and ensuring adherence to BOD 26-04 patching guidelines.
- EPSS (exploitation in the next 30 days)
- 0.35% (percentile 27)
- Assigned by
- microsoft
- NVD analysis
- Analyzed
- Record last updated
- Oct 8, 2026
- First seen by InfoSec Signals
- Oct 9, 2026
Affected products
Microsoft Windows 10 Version 1607 microsoft:windows_10_1607 | from 10.0.14393.0 before 10.0.14393.9339 | CNA record |
Microsoft Windows 10 Version 1809 microsoft:windows_10_1809 | from 10.0.17763.0 before 10.0.17763.9020 | CNA record |
Microsoft Windows Server 2012 microsoft:windows_server_2012 (from the name) | from 6.2.9200.0 before 6.2.9200.26226 | CNA record |
Microsoft Windows Server 2012 R2 microsoft:windows_server_2012_r2 (from the name) | from 6.3.9600.0 before 6.3.9600.23291 | CNA record |
Microsoft Windows Server 2016 microsoft:windows_server_2016 (from the name) | from 10.0.14393.0 before 10.0.14393.9339 | CNA record |
Microsoft Windows Server 2019 microsoft:windows_server_2019 (from the name) | from 10.0.17763.0 before 10.0.17763.9020 | CNA record |
Microsoft Windows Server 2022 microsoft:windows_server_2022 (from the name) | from 10.0.20348.0 before 10.0.20348.5386 | CNA record |
Microsoft Windows Server 2025 microsoft:windows_server_2025 (from the name) | from 10.0.26100.0 before 10.0.26100.33158 | CNA record |
microsoft windows_10_1607 microsoft:windows_10_1607 | before 10.0.14393.9339; before 10.0.14393.9339 | NVD |
microsoft windows_10_1809 microsoft:windows_10_1809 | before 10.0.17763.9020; before 10.0.17763.9020 | NVD |
microsoft windows_server_2012 microsoft:windows_server_2012 | all versions; r2 | NVD |
microsoft windows_server_2016 microsoft:windows_server_2016 | before 10.0.14393.9339 | NVD |
microsoft windows_server_2019 microsoft:windows_server_2019 | before 10.0.17763.9020 | NVD |
microsoft windows_server_2022 microsoft:windows_server_2022 | before 10.0.20348.5386 | NVD |
microsoft windows_server_2025 microsoft:windows_server_2025 | before 10.0.26100.33158 | NVD |
References
- https://msrc.microsoft.com/update-guide/vulnerability/CVE-2026-56155vendor-advisory, patch
The CVE record on cve.org NVD's entry
The CVE record is authoritative. Products marked “from the name” were identified from the CNA's free-text names, not a CPE, and are matched less certainly. This product uses the NVD API but is not endorsed or certified by the NVD.