CVE-2026-56155
KEVMicrosoft Active Directory Federation Services Insufficient Granularity of Access Control Vulnerability
Description
Microsoft Active Directory Federation Services contains an insufficient granularity of access control vulnerability that allows an authorized attacker to elevate privileges locally.
Insufficient granularity of access control in Active Directory Federation Services (AD FS) allows an authorized attacker to elevate privileges locally.
CVSS 3.1 vector
CVSS:3.1/AV:L/AC:L/PR:L/UI:N/S:U/C:H/I:H/A:HPublishedJul 14, 2026
Last modifiedJul 15, 2026
Added to KEVJul 14, 2026
Remediation dueJul 28, 2026
References
- msrc.microsoft.com/update-guide/vulnerability/CVE-2026-56155Vendor Advisory
- cisa.gov/known-exploited-vulnerabilities-catalog?field_cve=CVE-2026-56155US Government Resource
0 recent articles mention this CVE
69
Risk assessment · High
Actively exploited. Patch immediately.
- Exploitation
- Confirmed in the wild (CISA KEV)
- Federal remediation deadline
- Overdue by 91 days
- CVSS
- 7.8 HIGH
- EPSS (30-day exploit probability)
- 0.35% · top 72% of all CVEs
- Weakness
- CWE-1220
Recommended actions
- 1.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.
- 2.Treat as emergency change: patch or isolate internet-facing instances first.
- 3.Hunt for compromise: review logs for the disclosure window, not just from the patch date.
Assessment is derived automatically from the live signals above; verify against your own asset inventory.