CVE-2026-77505

Analyzed Analyzed - Analysis Complete

Use After Free in DNS Server Allows Remote Code Execution

Publication date: 2026-09-08

Last updated on: 2026-09-28

Assigner: Microsoft Corporation

Description

Use after free in DNS Server allows an unauthorized attacker to execute code over a network.

CVSS Scores

EPSS Scores

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Meta Information

Published

2026-09-08

Last Modified

2026-09-28

Generated

2026-09-29

AI Q&A

2026-09-10

EPSS Evaluated

2026-09-27

NVD

CVE-2026-77505

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-416	The product reuses or references memory after it has been freed. At some point afterward, the memory may be allocated again and saved in another pointer, while the original pointer references a location somewhere within the new allocation. Any operations using the original pointer are no longer valid because the memory "belongs" to the code that operates on the new pointer.

Attack-Flow Graph

Executive Summary

This is a use-after-free vulnerability in Microsoft's DNS Server. It allows an unauthorized attacker to execute arbitrary code remotely over a network by exploiting a memory corruption issue where the program tries to use memory that has already been freed.

Impact Analysis

An attacker could exploit this to run malicious code on your system, potentially taking control of your DNS server. This could lead to data breaches, service disruption, or further network compromise if the attacker gains elevated privileges.

Compliance Impact

This vulnerability could lead to unauthorized access or data exfiltration, violating confidentiality requirements in GDPR and HIPAA. Organizations may face compliance violations, fines, or legal consequences if exploited.

Mitigation Strategies

Apply the latest security updates from Microsoft for the DNS Server to patch the use-after-free vulnerability. Monitor Microsoft's advisory for patches and install them immediately.

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