Known Exploited Vulnerability
7.8
HIGH CVSS 3.1
CVE-2026-56155
Microsoft Active Directory Federation Services Insufficient Granularity of Access Control Vulnerability - [Actively Exploited]
Description

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

INFO

Published Date :

July 14, 2026, 5:17 p.m.

Last Modified :

July 15, 2026, 2:18 p.m.

Remotely Exploit :

No
CISA Notification
CISA KEV (Known Exploited Vulnerabilities)

For the benefit of the cybersecurity community and network defenders—and to help every organization better manage vulnerabilities and keep pace with threat activity—CISA maintains the authoritative source of vulnerabilities that have been exploited in the wild.

Description :

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

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.

Known Ransomware Campaign Use:

Unknown

Notes :

https://msrc.microsoft.com/update-guide/en-US/vulnerability/CVE-2026-56155 ; BOD 26-04: https://www.cisa.gov/news-events/directives/bod-26-04-prioritizing-security-updates-based-risk ; Forensics Triage Requirements: https://www.cisa.gov/news-events/directives/bod-26-04-implementation-guidance-prioritizing-security-updates-based-risk ; https://nvd.nist.gov/vuln/detail/CVE-2026-56155; https://learn.microsoft.com/en-us/windows-server/identity/ad-fs/decommission/adfs-decommission-guide

Affected Products

The following products are affected by CVE-2026-56155 vulnerability. Even if cvefeed.io is aware of the exact versions of the products that are affected, the information is not represented in the table below.

ID Vendor Product Action
1 Microsoft windows_10
2 Microsoft windows_server_2012
3 Microsoft windows_server_2016
4 Microsoft windows_server_2019
5 Microsoft windows_10_1607
6 Microsoft windows_10_1809
7 Microsoft windows_server_2022
8 Microsoft windows_server_2012_r2
9 Microsoft windows_server_2025
CVSS Scores
The Common Vulnerability Scoring System is a standardized framework for assessing the severity of vulnerabilities in software and systems. We collect and displays CVSS scores from various sources for each CVE.
Score Version Severity Vector Exploitability Score Impact Score Source
CVSS 134c704f-9b21-4f2e-91b3-4a467353bcc0
CVSS 3.1 HIGH f38d906d-7342-40ea-92c1-6c4a2c6478c8
CVSS 3.1 HIGH [email protected]
Public PoC/Exploit Available at Github

CVE-2026-56155 has a 5 public PoC/Exploit available at Github. Go to the Public Exploits tab to see the list.

References to Advisories, Solutions, and Tools

Here, you will find a curated list of external links that provide in-depth information, practical solutions, and valuable tools related to CVE-2026-56155.

URL Resource
https://msrc.microsoft.com/update-guide/vulnerability/CVE-2026-56155 Vendor Advisory
https://www.cisa.gov/known-exploited-vulnerabilities-catalog?field_cve=CVE-2026-56155 US Government Resource
CWE - Common Weakness Enumeration

While CVE identifies specific instances of vulnerabilities, CWE categorizes the common flaws or weaknesses that can lead to vulnerabilities. CVE-2026-56155 is associated with the following CWEs:

Common Attack Pattern Enumeration and Classification (CAPEC)

Common Attack Pattern Enumeration and Classification (CAPEC) stores attack patterns, which are descriptions of the common attributes and approaches employed by adversaries to exploit the CVE-2026-56155 weaknesses.

We scan GitHub repositories to detect new proof-of-concept exploits. Following list is a collection of public exploits and proof-of-concepts, which have been published on GitHub (sorted by the most recently updated).

End-to-end technical analysis and reproduction notes for high-impact CVEs (e.g., pre-auth RCEs, sandbox escapes, and privilege escalations).

Updated: 1 week, 5 days ago
0 stars 0 fork 0 watcher
Born at : July 21, 2026, 3:46 a.m. This repo has been linked 13 different CVEs too.

Panel de ciberamenazas que se actualiza solo: nuevas amenazas y vulnerabilidades activas cada 6 horas.

CSS Python HTML JavaScript

Updated: 2 weeks, 1 day ago
0 stars 0 fork 0 watcher
Born at : Jan. 28, 2026, 12:11 a.m. This repo has been linked 16 different CVEs too.

None

Ruby Shell Python

Updated: 2 weeks, 4 days ago
1 stars 0 fork 0 watcher
Born at : Nov. 6, 2025, 3:20 a.m. This repo has been linked 4 different CVEs too.

None

Python

Updated: 2 weeks, 1 day ago
2 stars 1 fork 1 watcher
Born at : Oct. 29, 2024, 8:10 p.m. This repo has been linked 10 different CVEs too.

None

Python

Updated: 2 weeks, 2 days ago
0 stars 0 fork 0 watcher
Born at : Sept. 13, 2024, 9:56 p.m. This repo has been linked 4 different CVEs too.

Results are limited to the first 15 repositories due to potential performance issues.

The following list is the news that have been mention CVE-2026-56155 vulnerability anywhere in the article.

  • The Cyber Express
The Cyber Express Weekly Roundup: TikTok Age Verification Probe, Healthcare Data Breach, Qantas Ruling, and Major Cyberattacks

This week’s cybersecurity roundup highlights growing concerns around online child safety, healthcare data protection, supply chain risks, and cyber threats affecting organizations worldwide. From regu ... Read more

Published Date: Jul 17, 2026 (2 weeks, 3 days ago)
  • Kaspersky
Key vulnerabilities of Microsoft’s July 2026 Patch Tuesday

Although experts had already warned of an impending “tsunami of vulnerabilities” back in April, immediately following the announcement of the Mythos AI model, concrete evidence began to emerge over th ... Read more

Published Date: Jul 15, 2026 (2 weeks, 5 days ago)
  • The Hacker News
Researcher Drops New Windows Zero-Day PoC Hours After Microsoft Patch Tuesday

Security researcher Chaotic Eclipse (aka Nightmare-Eclipse) has released a new proof-of-concept (PoC) exploit called LegacyHive. It has been described as a Windows User Profile Service arbitrary hive ... Read more

Published Date: Jul 15, 2026 (2 weeks, 5 days ago)
  • The Cyber Express
Microsoft’s Largest Patch Tuesday Fixes 622 Vulnerabilities, Two Under Active Attack

Microsoft Patch Tuesday July 2026 delivered the company’s largest security update to date, addressing 622 Microsoft CVEs, more than tripling the roughly 200 vulnerabilities patched in June. Among the ... Read more

Published Date: Jul 15, 2026 (2 weeks, 5 days ago)
  • security.nl
Microsoft komt met grootste Patch Tuesday ooit: 622 kwetsbaarheden gefixt

Microsoft heeft gisteren tijdens Patch Tuesday het grootste aantal kwetsbaarheden ooit verholpen, namelijk 622. Het techbedrijf liet een aantal dagen geleden weten dat klanten en gebruikers als gevolg ... Read more

Published Date: Jul 15, 2026 (2 weeks, 5 days ago)
  • CrowdStrike.com
July 2026 Patch Tuesday: Microsoft Patches 622 Vulnerabilities Including Two Exploited Zero-Days

Microsoft has addressed 622 vulnerabilities in its July 2026 security update release. Based on CrowdStrike’s analysis, this represents roughly triple the number of vulnerabilities in June, and almost ... Read more

Published Date: Jul 15, 2026 (2 weeks, 5 days ago)
  • The Hacker News
Microsoft Patches Record 622 Flaws, Including Two Zero-Days Under Active Attack

Microsoft shipped its largest Patch Tuesday on record today, and two of the fixes close holes that attackers are already exploiting. The release covers 622 of Microsoft's own CVEs by its Security Upda ... Read more

Published Date: Jul 14, 2026 (2 weeks, 6 days ago)

The following table lists the changes that have been made to the CVE-2026-56155 vulnerability over time.

Vulnerability history details can be useful for understanding the evolution of a vulnerability, and for identifying the most recent changes that may impact the vulnerability's severity, exploitability, or other characteristics.

  • CVE Modified by 134c704f-9b21-4f2e-91b3-4a467353bcc0

    Jul. 15, 2026

    Action Type Old Value New Value
    Changed SSVC {'id': 'CVE-2026-56155', 'role': 'CISA Coordinator', 'options': [{'exploitation': 'active'}, {'automatable': 'no'}, {'technicalImpact': 'total'}], 'version': '2.0.3', 'timestamp': '2026-07-09T00:00:00+00:00'} {'id': 'CVE-2026-56155', 'role': 'CISA Coordinator', 'options': [{'exploitation': 'active'}, {'automatable': 'no'}, {'technicalImpact': 'total'}], 'version': '2.0.3', 'timestamp': '2026-07-15T03:55:53.880960Z'}
  • CVE Modified by 134c704f-9b21-4f2e-91b3-4a467353bcc0

    Jul. 15, 2026

    Action Type Old Value New Value
    Changed SSVC {'id': 'CVE-2026-56155', 'role': 'CISA Coordinator', 'options': [{'exploitation': 'active'}, {'automatable': 'no'}, {'technicalImpact': 'total'}], 'version': '2.0.3', 'timestamp': '2026-07-14T18:45:04.836579Z'} {'id': 'CVE-2026-56155', 'role': 'CISA Coordinator', 'options': [{'exploitation': 'active'}, {'automatable': 'no'}, {'technicalImpact': 'total'}], 'version': '2.0.3', 'timestamp': '2026-07-09T00:00:00+00:00'}
  • Initial Analysis by [email protected]

    Jul. 14, 2026

    Action Type Old Value New Value
    Added CPE Configuration OR *cpe:2.3:o:microsoft:windows_server_2012:r2:*:*:*:*:*:*:* *cpe:2.3:o:microsoft:windows_server_2012:-:*:*:*:*:*:*:* *cpe:2.3:o:microsoft:windows_10_1607:*:*:*:*:*:*:x64:* versions up to (excluding) 10.0.14393.9339 *cpe:2.3:o:microsoft:windows_10_1607:*:*:*:*:*:*:x86:* versions up to (excluding) 10.0.14393.9339 *cpe:2.3:o:microsoft:windows_10_1809:*:*:*:*:*:*:x64:* versions up to (excluding) 10.0.17763.9020 *cpe:2.3:o:microsoft:windows_10_1809:*:*:*:*:*:*:x86:* versions up to (excluding) 10.0.17763.9020 *cpe:2.3:o:microsoft:windows_server_2016:*:*:*:*:*:*:*:* versions up to (excluding) 10.0.14393.9339 *cpe:2.3:o:microsoft:windows_server_2019:*:*:*:*:*:*:*:* versions up to (excluding) 10.0.17763.9020 *cpe:2.3:o:microsoft:windows_server_2022:*:*:*:*:*:*:*:* versions up to (excluding) 10.0.20348.5386 *cpe:2.3:o:microsoft:windows_server_2025:*:*:*:*:*:*:*:* versions up to (excluding) 10.0.26100.33158
    Added Reference Type Microsoft Corporation: https://msrc.microsoft.com/update-guide/vulnerability/CVE-2026-56155 Types: Vendor Advisory
    Added Reference Type CISA-ADP: https://www.cisa.gov/known-exploited-vulnerabilities-catalog?field_cve=CVE-2026-56155 Types: US Government Resource
  • CVE Modified by 134c704f-9b21-4f2e-91b3-4a467353bcc0

    Jul. 14, 2026

    Action Type Old Value New Value
    Added Reference https://www.cisa.gov/known-exploited-vulnerabilities-catalog?field_cve=CVE-2026-56155
    Added SSVC {'id': 'CVE-2026-56155', 'role': 'CISA Coordinator', 'options': [{'exploitation': 'active'}, {'automatable': 'no'}, {'technicalImpact': 'total'}], 'version': '2.0.3', 'timestamp': '2026-07-14T18:45:04.836579Z'}
  • CVE CISA KEV Update by 9119a7d8-5eab-497f-8521-727c672e3725

    Jul. 14, 2026

    Action Type Old Value New Value
    Added Date Added 2026-07-14
    Added Due Date 2026-07-14
    Added Required Action 2026-07-14
    Added Vulnerability Name 2026-07-14
  • New CVE Received by [email protected]

    Jul. 14, 2026

    Action Type Old Value New Value
    Added Affected [{'vendor': 'Microsoft', 'product': 'Windows 10 Version 1607', 'versions': [{'status': 'affected', 'version': '10.0.14393.0', 'lessThan': '10.0.14393.9339', 'versionType': 'custom'}], 'platforms': ['32-bit Systems', 'x64-based Systems']}, {'vendor': 'Microsoft', 'product': 'Windows 10 Version 1809', 'versions': [{'status': 'affected', 'version': '10.0.17763.0', 'lessThan': '10.0.17763.9020', 'versionType': 'custom'}], 'platforms': ['32-bit Systems', 'x64-based Systems']}, {'vendor': 'Microsoft', 'product': 'Windows Server 2012', 'versions': [{'status': 'affected', 'version': '6.2.9200.0', 'lessThan': '6.2.9200.26226', 'versionType': 'custom'}], 'platforms': ['x64-based Systems']}, {'vendor': 'Microsoft', 'product': 'Windows Server 2012 (Server Core installation)', 'versions': [{'status': 'affected', 'version': '6.2.9200.0', 'lessThan': '6.2.9200.26226', 'versionType': 'custom'}], 'platforms': ['x64-based Systems']}, {'vendor': 'Microsoft', 'product': 'Windows Server 2012 R2', 'versions': [{'status': 'affected', 'version': '6.3.9600.0', 'lessThan': '6.3.9600.23291', 'versionType': 'custom'}], 'platforms': ['x64-based Systems']}, {'vendor': 'Microsoft', 'product': 'Windows Server 2012 R2 (Server Core installation)', 'versions': [{'status': 'affected', 'version': '6.3.9600.0', 'lessThan': '6.3.9600.23291', 'versionType': 'custom'}], 'platforms': ['x64-based Systems']}, {'vendor': 'Microsoft', 'product': 'Windows Server 2016', 'versions': [{'status': 'affected', 'version': '10.0.14393.0', 'lessThan': '10.0.14393.9339', 'versionType': 'custom'}], 'platforms': ['x64-based Systems']}, {'vendor': 'Microsoft', 'product': 'Windows Server 2016 (Server Core installation)', 'versions': [{'status': 'affected', 'version': '10.0.14393.0', 'lessThan': '10.0.14393.9339', 'versionType': 'custom'}], 'platforms': ['x64-based Systems']}, {'vendor': 'Microsoft', 'product': 'Windows Server 2019', 'versions': [{'status': 'affected', 'version': '10.0.17763.0', 'lessThan': '10.0.17763.9020', 'versionType': 'custom'}], 'platforms': ['x64-based Systems']}, {'vendor': 'Microsoft', 'product': 'Windows Server 2019 (Server Core installation)', 'versions': [{'status': 'affected', 'version': '10.0.17763.0', 'lessThan': '10.0.17763.9020', 'versionType': 'custom'}], 'platforms': ['x64-based Systems']}, {'vendor': 'Microsoft', 'product': 'Windows Server 2022', 'versions': [{'status': 'affected', 'version': '10.0.20348.0', 'lessThan': '10.0.20348.5386', 'versionType': 'custom'}], 'platforms': ['x64-based Systems']}, {'vendor': 'Microsoft', 'product': 'Windows Server 2025', 'versions': [{'status': 'affected', 'version': '10.0.26100.0', 'lessThan': '10.0.26100.33158', 'versionType': 'custom'}], 'platforms': ['x64-based Systems']}, {'vendor': 'Microsoft', 'product': 'Windows Server 2025 (Server Core installation)', 'versions': [{'status': 'affected', 'version': '10.0.26100.0', 'lessThan': '10.0.26100.33158', 'versionType': 'custom'}], 'platforms': ['x64-based Systems']}]
    Added Description Insufficient granularity of access control in Active Directory Federation Services (AD FS) allows an authorized attacker to elevate privileges locally.
    Added CVSS V3.1 AV:L/AC:L/PR:L/UI:N/S:U/C:H/I:H/A:H
    Added CWE CWE-1220
    Added Reference https://msrc.microsoft.com/update-guide/vulnerability/CVE-2026-56155
EPSS is a daily estimate of the probability of exploitation activity being observed over the next 30 days. Following chart shows the EPSS score history of the vulnerability.