CVE-2026-56155
Insufficient granularity of access control in Active Directory Federation Services (AD FS) allows an authorized attacker to elevate privileges locally.
Actively exploited
- In the CISA exploited-vulnerabilities catalogue since Jul 14, 2026
- US federal agencies must remediate it by Jul 28, 2026 (BOD 22-01)
- Attacked 1 day before the vulnerability was made public
Apply 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.
Source: CISA KEV · Aug 17, 2026 Aug 7, 2026 Jul 20, 2026 Jul 14, 2026 Jul 14, 2026 Jul 14, 2026
CVSS:3.1/AV:L/AC:L/PR:L/UI:N/S:U/C:H/I:H/A:HAffected products
| Vendors | Product | Versions |
|---|---|---|
| microsoft | windows 10 1607 | < 10.0.14393.9339 |
| microsoft | windows 10 1809 | < 10.0.17763.9020 |
| microsoft | windows server 2012 | - |
| microsoft | windows server 2016 | < 10.0.14393.9339 |
| microsoft | windows server 2019 | < 10.0.17763.9020 |
| microsoft | windows server 2022 | < 10.0.20348.5386 |
| microsoft | windows server 2025 | < 10.0.26100.33158 |
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