CVE-2026-56155 HIGH

CVE-2026-56155: Active Directory Federation Services Elevation of Privilege Vulnerability

Vendor Microsoft
Product Windows 10 Version 1607
Weakness CWE-1220
KEV Status Known Exploited
Published July 14, 2026
Last update July 24, 2026
View on NVD All CVEs

CVSS base score

7.8/10
Attack vector Local
Attack complexity Low
Privileges required Low
User interaction None
Confidentiality High
Integrity High

CVSS vector

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

What the vulnerability does

01Description

Insufficient granularity of access control in Active Directory Federation Services (AD FS) allows an authorized attacker to elevate privileges locally.

CISA mandated remediation

02CISA Required Action

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.

Key dates

03Disclosure timeline

July 14, 2026 CVE published
July 24, 2026 Record updated

External resources

04References

NVD — National Vulnerability Database https://nvd.nist.gov/vuln/detail/CVE-2026-56155 CWE — Common Weakness Enumeration https://cwe.mitre.org/data/definitions/1220.html AskarLabs — CWE-1220 write-up Insufficient Granularity of Access Control CISA KEV Reference https://msrc.microsoft.com/update-guide/en-US/vulnerability/CV… CISA KEV Reference https://www.cisa.gov/news-events/directives/bod-26-04-prioriti… CISA KEV Reference https://www.cisa.gov/news-events/directives/bod-26-04-implemen… CISA KEV Reference https://nvd.nist.gov/vuln/detail/CVE-2026-56155 CISA KEV Reference https://learn.microsoft.com/en-us/windows-server/identity/ad-f…