Vulnerability · CVE-2026-56155
Microsoft Active Directory Federation Services Insufficient Granularity of Access Control Vulnerability
Published Jul 14, 2026 · catalog updated Jul 15, 2026 · Microsoft Active Directory Federation Services
Patch now
CVE-2026-56155 is in the CISA known-exploited catalog, due Jul 28, 2026. Confirm Microsoft Active Directory Federation Services against the vendor advisory and apply that fix. The CVSS score does not change the priority.
Gaps on this record
- No version range is stored. A customer cannot check an installed version against this record.
- Severity
- High7.8
- Known exploitation
- CISA KEV and VulnCheck KEV
- EPSS
- 0.35%
- Remediation
- Remediation guidance
- Affected products
- cpe microsoft/windows 10 1607 · cpe microsoft/windows 10 1809 · cpe microsoft/windows server 2012 · cpe microsoft/windows server 2016 · cpe microsoft/windows server 2019 · vendor Microsoft Active Directory Federation Services
Microsoft Active Directory Federation Services contains an insufficient granularity of access control vulnerability that allows an authorized attacker to elevate privileges locally.
Are you affected?
Enter the version you run. The result uses only the ranges stored on this record.
The check returns affected, not affected, or incomplete. It does not guess a version that is missing from the record.
- cpe microsoft/windows 10 1607version unspecified
- cpe microsoft/windows 10 1809version unspecified
- cpe microsoft/windows server 2012r2
- cpe microsoft/windows server 2016version unspecified
- cpe microsoft/windows server 2019version unspecified
- vendor Microsoft Active Directory Federation Servicesversion unspecified
How to fix CVE-2026-56155
Recommended remediation
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. CISA due date Jul 28, 2026.
Official advisories
What to do
Three questions, each answered from this record only. Confirm the vendor advisory before you patch.
Should you patch?
CVE-2026-56155 is in the CISA known-exploited catalog, due Jul 28, 2026. Confirm Microsoft Active Directory Federation Services against the vendor advisory and apply that fix. The CVSS score does not change the priority.
Which versions are affected?
Compare what you have installed with microsoft/windows server 2012 r2. 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.
What should an analyst verify?
CWE-1220. EPSS 0.35%. The CISA KEV listing is the exploitation evidence. No Exploit-DB or Metasploit reference is linked. Use the source links for the original advisory.
Technology hubs
Code
The project this record applies to. Exploit listings stay in References.
No public source repository is identified for this product.
Timeline
Detection, updates, and resolution for this record.
Jul 14, 2026 · Catalog
Detected
Microsoft Active Directory Federation Services contains an insufficient granularity of access control vulnerability that allows an authorized attacker to elevate privileges locally.
Jul 14, 2026 · CISA KEV
Known exploited
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
Jul 15, 2026 · Catalog
Updated
Microsoft Active Directory Federation Services contains an insufficient granularity of access control vulnerability that allows an authorized attacker to elevate privileges locally.
Jul 28, 2026 · CISA KEV
Remediation due
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
Sources
- CISA KEVConfirmed exploitationCVE-2026-56155
Microsoft Active Directory Federation Services contains an insufficient granularity of access control vulnerability that allows an authorized attacker to elevate privileges locally.
cisa.gov - CVE.orgVulnerability recordCVE-2026-56155
Official CVE identifier
cve.org - FIRST EPSSExploitation probabilityCVE-2026-56155
30-day exploitation probability 0.3%
first.org - JPCERT/CCGovernment advisoryCVE-2026-56155
[Updated] Microsoft Releases July 2026 Security Updates
jpcert.or.jp - NIST NVDVulnerability recordCVE-2026-56155
Insufficient granularity of access control in Active Directory Federation Services (AD FS) allows an authorized attacker to elevate privileges locally.
nvd.nist.gov - VulnCheck KEVConfirmed exploitationCVE-2026-56155
Microsoft Active Directory Federation Services contains an insufficient granularity of access control vulnerability that allows an authorized attacker to elevate privileges locally.
vulncheck.com
References
- VulnCheck exploitation evidence · api.msrc.microsoft.com
- VulnCheck exploitation evidence · docs.google.com
- CISA note · learn.microsoft.com
- CISA note · msrc.microsoft.com
- Vendor Advisory · msrc.microsoft.com
- CISA note · nvd.nist.gov
- VulnCheck exploitation evidence · previdian.com
- VulnCheck exploitation evidence · research.checkpoint.com
- US Government Resource · cisa.gov
- CISA note · cisa.gov
- CISA note · cisa.gov
- VulnCheck exploitation evidence · cisa.gov
Freshness
Last verified in this catalog Oct 18, 2026. Significant claims (KEV, EPSS, CVSS, affected ranges) come from the source rows above — open the original publisher for the authoritative advisory.