Microsoft Active Directory Federation Services Insufficient Access Control Allows an Authorized Attacker to Elevate Privileges Locally; CISA's July 28th KEV Deadline Has Passed

Last refreshed2026-09-27

Status: KEV | Advisory ID: CVE-2026-56155

Key Details

CVE	CVE-2026-56155
Vulnerability Name	Microsoft Active Directory Federation Services Insufficient Granularity of Access Control Vulnerability
Affected products	Microsoft Active Directory Federation Services
Exploitation status	Listed in CISA's Known Exploited Vulnerabilities (KEV) catalog, indicating confirmed active exploitation.
Classified as	CWE-1220 (Insufficient Granularity of Access Control)
KEV listing	Added to CISA's Known Exploited Vulnerabilities (KEV) catalog on 2026-07-14.
Exploitation prediction (EPSS)	0.35% probability of exploitation in the next 30 days (26% percentile) -- FIRST.org's EPSS model.
Federal remediation deadline	2026-07-28 (CISA KEV, Binding Operational Directive).

Affected Products, Subsystems & Sectors

Vendor	Product	Affected Versions	Patch Status
Microsoft	Active Directory Federation Services

Vendor

Product

Affected Versions

Patch Status

Microsoft

Active Directory Federation Services

Subsystems	General OT
Sectors	Multiple

What to Know

Microsoft Active Directory Federation Services contains an insufficient granularity of access control vulnerability that allows an authorized attacker to elevate privileges locally.

What to Do

Monitor Microsoft's web page for any future patch releases.

References

Source	Reference
NVD	https://nvd.nist.gov/vuln/detail/CVE-2026-56155
CVE	https://www.cve.org/CVERecord?id=CVE-2026-56155

Source

Reference

NVD

https://nvd.nist.gov/vuln/detail/CVE-2026-56155

CVE

https://www.cve.org/CVERecord?id=CVE-2026-56155

KEV Required Action

Field	Value
KEV Link	https://www.cisa.gov/known-exploited-vulnerabilities-catalog
Date Added to KEV	2026-07-14
Required Action Due Date	2026-07-28
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.

Field

Value

KEV Link

https://www.cisa.gov/known-exploited-vulnerabilities-catalog

Date Added to KEV

2026-07-14

Required Action Due Date

2026-07-28

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.