Exploited vulnerabilities / CVE-2026-56155
Confirmed exploited · privilege escalation · Microsoft Active Directory Federation ServicesCVE-2026-56155
Microsoft Active Directory Federation Services privilege escalation, confirmed exploited in the wild.
Microsoft Active Directory Federation Services contains an insufficient granularity of access control vulnerability that allows an authorized attacker to elevate privileges locally.
| CISA's name for it | Microsoft Active Directory Federation Services Insufficient Granularity of Access Control Vulnerability |
|---|---|
| Vendor and product | Microsoft · Active Directory Federation Services |
| Type | privilege escalation · CWE-1220 |
| Exploited | Confirmed by CISA listed 14 July 2026 |
| Likelihood | scored lower by EPSS, but already confirmed exploited, which outranks any prediction |
| Deadline | 28 July 2026 · already passed |
| Used in ransomware | Not reported |
| Advisories | msrc.microsoft.com ↗ · www.cisa.gov ↗ · www.cisa.gov ↗ · nvd.nist.gov ↗ |
Three steps, in this order
Install the update on every affected system, servers and workstations alike.
Escalation bugs are chained after a first foothold: check for other exposures an attacker could start from.
Review who holds administrative rights, and alert on new ones.
| CISA's 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. |
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Know before someone else finds it
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CVE-2026-56155 in short
Is CVE-2026-56155 being exploited?
Yes. CISA added CVE-2026-56155 to its Known Exploited Vulnerabilities catalogue on 14 July 2026, which it does only on evidence of exploitation in the wild.
What is the CISA deadline for CVE-2026-56155?
US federal agencies must remediate it by 28 July 2026. Everyone else should treat that date as the latest safe point to patch an internet-facing system.
How likely is CVE-2026-56155 to be exploited in the next 30 days?
FIRST's Exploit Prediction Scoring System gives it 0.3%, the 28th percentile of every CVE it scores.
How do I fix CVE-2026-56155?
Install the update on every affected system, servers and workstations alike. Escalation bugs are chained after a first foothold: check for other exposures an attacker could start from. Review who holds administrative rights, and alert on new ones.
Other Microsoft vulnerabilities being exploited
| CVE | Product | Type | Listed |
|---|---|---|---|
| CVE-2026-124194 | Office | exploited vulnerability | 10 November 2026 |
| CVE-2026-96951 | Windows | command injection | 13 October 2026 |
| CVE-2026-65660 | SharePoint | exploited vulnerability | 25 September 2026 |
| CVE-2026-81963 | Windows | privilege escalation | 8 September 2026 |
| CVE-2026-85880 | Windows | privilege escalation | 8 September 2026 |
| CVE-2019-1068 | SQL Server | remote code execution | 26 August 2026 |
Sources: CISA Known Exploited Vulnerabilities catalogue (released 10 November 2026) and FIRST EPSS. Page compiled automatically by SAK T.L.M, the threat-intelligence tool of SAK T.E.C, on 13 November 2026.