Improper Output Encoding in Active Directory Certificate Services

Publication date: 2026-09-08

Last updated on: 2026-09-24

Assigner: Microsoft Corporation

Description

Improper encoding or escaping of output in Active Directory Certificate Services (AD CS) allows an authorized attacker to elevate privileges locally.

CVSS Scores

EPSS Scores

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Meta Information

Published

2026-09-08

Last Modified

2026-09-24

Generated

2026-09-29

AI Q&A

2026-09-10

EPSS Evaluated

2026-09-27

NVD

CVE-2026-69821

Affected Vendors & Products

Vendor	Product	Version / Range
microsoft	windows_server_2012	r2
microsoft	windows_server_2012	*
microsoft	windows_10_1607	to 10.0.14393.9512 (exc)
microsoft	windows_10_1607	to 10.0.14393.9512 (exc)
microsoft	windows_10_1809	to 10.0.17763.9245 (exc)
microsoft	windows_10_1809	to 10.0.17763.9245 (exc)
microsoft	windows_server_2025	to 10.0.26100.33438 (exc)
microsoft	windows_server_2016	to 10.0.14393.9512 (exc)
microsoft	windows_server_2019	to 10.0.17763.9245 (exc)
microsoft	windows_server_2022	to 10.0.20348.5622 (exc)

Helpful Resources

Exploitability

CWE

KEV

CWE ID	Description
CWE-116	The product prepares a structured message for communication with another component, but encoding or escaping of the data is either missing or done incorrectly. As a result, the intended structure of the message is not preserved.

Attack-Flow Graph

Executive Summary

This vulnerability involves improper encoding or escaping of output in Active Directory Certificate Services (AD CS). An authorized attacker can exploit this to elevate their privileges locally on the system.

Impact Analysis

An attacker with local access could exploit this to gain higher privileges, potentially allowing them to take control of the system or perform unauthorized actions.

Mitigation Strategies

Apply the latest security updates from Microsoft for Active Directory Certificate Services as soon as possible to address the improper encoding or escaping issue.

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