Description
Use of externally-controlled format string in Active Directory Certificate Services (AD CS) allows an authorized attacker to disclose information over a network.
Published: 2026-09-08
Score: 6.5 Medium
EPSS: n/a
KEV: No
Impact: n/a
Action: n/a
AI Analysis

Impact

An externally‑controlled format string vulnerability resides in the Active Directory Certificate Services (AD CS) component. The flaw allows an attacker who has authorized access to AD CS to supply format specifiers that can cause the service to reveal sensitive internal data to the network. The weakness matches CWE-134, which can expose confidential configuration or credential information, compromising the confidentiality of the affected systems.

Affected Systems

Microsoft Windows platforms listed in the CNA vendor/product entries are impacted. Specifically, Windows 10 Version 1607 and 1809, Windows Server 2012, Windows Server 2012 R2, Windows Server 2016, Windows Server 2019, Windows Server 2022, Windows Server 2025, and their Server Core installation variants are all affected. No version ranges are provided beyond the listed releases, so any system running one of these builds is susceptible unless updated.

Risk and Exploitability

The CVSS score of 6.5 places this incident in the moderate severity range. EPSS data are currently unavailable, making precise probability assessment uncertain, but the requirement for authorized access suggests the exposure is limited to users with sufficient privileges on the AD CS service. The vulnerability is not currently listed in the CISA KEV catalog, so no confirmed public exploits are known. Nevertheless, the combination of a format‑string flaw and the potential to leak sensitive configuration details warrants prompt remediation.

Generated by OpenCVE AI on September 8, 2026 at 20:59 UTC.

Remediation

No vendor fix or workaround currently provided.

OpenCVE Recommended Actions

  • Install the Microsoft security update that addresses the format‑string vulnerability in AD CS, as published in the official Microsoft Update Catalog (refer to the advisory at https://msrc.microsoft.com/update-guide/vulnerability/CVE-2026-69395).
  • Restrict user or service accounts that interact with AD CS to the minimum required permissions, ensuring that only trusted operators can invoke the certificate services.
  • Enable auditing for AD CS‑related activities and monitor event logs for anomalous request patterns or repeated error messages that may indicate exploitation attempts.

Generated by OpenCVE AI on September 8, 2026 at 20:59 UTC.

Tracking

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Advisories

No advisories yet.

History

Tue, 08 Sep 2026 21:30:00 +0000

Type Values Removed Values Added
Metrics ssvc

{'options': {'Automatable': 'no', 'Exploitation': 'none', 'Technical Impact': 'partial'}, 'version': '2.0.3'}

Tue, 08 Sep 2026 17:30:00 +0000

Type Values Removed Values Added
Description Use of externally-controlled format string in Active Directory Certificate Services (AD CS) allows an authorized attacker to disclose information over a network.
Title Active Directory Certificate Services (AD CS) Information Disclosure Vulnerability
First Time appeared Microsoft
Microsoft windows 10 1607
Microsoft windows 10 1809
Microsoft windows Server 2012
Microsoft windows Server 2012 R2
Microsoft windows Server 2016
Microsoft windows Server 2019
Microsoft windows Server 2022
Microsoft windows Server 2025
Weaknesses CWE-134
CPEs cpe:2.3:o:microsoft:windows_10_1607:*:*:*:*:*:*:x86:*
cpe:2.3:o:microsoft:windows_10_1809:*:*:*:*:*:*:x86:*
cpe:2.3:o:microsoft:windows_server_2012:*:*:*:*:*:*:x64:*
cpe:2.3:o:microsoft:windows_server_2012_R2:*:*:*:*:*:*:x64:*
cpe:2.3:o:microsoft:windows_server_2016:*:*:*:*:*:*:*:*
cpe:2.3:o:microsoft:windows_server_2019:*:*:*:*:*:*:*:*
cpe:2.3:o:microsoft:windows_server_2022:*:*:*:*:*:*:*:*
cpe:2.3:o:microsoft:windows_server_2025:*:*:*:*:*:*:*:*
Vendors & Products Microsoft
Microsoft windows 10 1607
Microsoft windows 10 1809
Microsoft windows Server 2012
Microsoft windows Server 2012 R2
Microsoft windows Server 2016
Microsoft windows Server 2019
Microsoft windows Server 2022
Microsoft windows Server 2025
References
Metrics cvssV3_1

{'score': 6.5, 'vector': 'CVSS:3.1/AV:N/AC:L/PR:L/UI:N/S:U/C:H/I:N/A:N/E:U/RL:O/RC:C'}

Subscriptions

Microsoft Windows 10 1607 Windows 10 1809 Windows Server 2012 Windows Server 2012 R2 Windows Server 2016 Windows Server 2019 Windows Server 2022 Windows Server 2025
cve-icon MITRE

Status: PUBLISHED

Assigner: microsoft

Published:

Updated: 2026-09-08T20:08:06.186Z

Reserved: 2026-08-03T20:57:58.962Z

Link: CVE-2026-69395

cve-icon Vulnrichment

Updated: 2026-09-08T20:07:59.629Z

cve-icon NVD

Status : Awaiting Analysis

Published: 2026-09-08T18:19:01.710

Modified: 2026-09-08T20:17:49.763

Link: CVE-2026-69395

cve-icon Redhat

No data.

cve-icon OpenCVE Enrichment

Updated: 2026-09-08T21:00:12Z

Weaknesses
  • CWE-134

    Use of Externally-Controlled Format String