CVE-2026-70304

Analyzed Analyzed - Analysis Complete

Heap-based Buffer Overflow in Windows DNS

Publication date: 2026-08-11

Last updated on: 2026-08-17

Assigner: Microsoft Corporation

Description

Heap-based buffer overflow in Windows DNS allows an authorized attacker to elevate privileges locally.

CVSS Scores

EPSS Scores

Probability:
Percentile:

Meta Information

Published

2026-08-11

Last Modified

2026-08-17

Generated

2026-09-01

AI Q&A

2026-08-12

EPSS Evaluated

2026-08-30

NVD

CVE-2026-70304

EUVD

EUVD-2026-56586

Affected Vendors & Products

Vendor	Product	Version / Range
microsoft	windows_server_2012	r2
microsoft	windows_server_2012	*
microsoft	windows_10_1607	to 10.0.14393.9418 (exc)
microsoft	windows_10_1607	to 10.0.14393.9418 (exc)
microsoft	windows_10_21h2	to 10.0.19044.7663 (exc)
microsoft	windows_10_21h2	to 10.0.19044.7663 (exc)
microsoft	windows_10_21h2	to 10.0.19044.7663 (exc)
microsoft	windows_10_22h2	to 10.0.19045.7663 (exc)
microsoft	windows_10_22h2	to 10.0.19045.7663 (exc)
microsoft	windows_10_22h2	to 10.0.19045.7663 (exc)
microsoft	windows_11_23h2	to 10.0.22631.7517 (exc)
microsoft	windows_11_23h2	to 10.0.22631.7517 (exc)
microsoft	windows_11_24h2	to 10.0.26100.9106 (exc)
microsoft	windows_11_24h2	to 10.0.26100.9106 (exc)
microsoft	windows_11_26h1	to 10.0.28000.2704 (exc)
microsoft	windows_11_26h1	to 10.0.28000.2704 (exc)
microsoft	windows_11_25h2	to 10.0.26200.9106 (exc)
microsoft	windows_11_25h2	to 10.0.26200.9106 (exc)
microsoft	windows_server_2016	to 10.0.14393.9418 (exc)
microsoft	windows_server_2022	to 10.0.20348.5440 (exc)
microsoft	windows_server_2025	to 10.0.26100.33222 (exc)
microsoft	windows_10_1809	to 10.0.17763.9121 (exc)
microsoft	windows_10_1809	to 10.0.17763.9121 (exc)
microsoft	windows_server_2019	to 10.0.17763.9121 (exc)

Helpful Resources

Exploitability

CWE

KEV

CWE ID	Description
CWE-122	A heap overflow condition is a buffer overflow, where the buffer that can be overwritten is allocated in the heap portion of memory, generally meaning that the buffer was allocated using a routine such as malloc().

Attack-Flow Graph

Executive Summary

This is a heap-based buffer overflow vulnerability in Windows DNS that allows an authorized attacker to elevate their privileges locally. A heap-based buffer overflow occurs when a program writes more data to a buffer than it can hold, corrupting adjacent memory and potentially allowing arbitrary code execution.

Detection Guidance

Detection requires checking for Windows DNS service vulnerabilities. Use Windows Update to apply patches. Monitor for unusual DNS service behavior or crashes. Check Event Viewer logs for DNS-related errors.

Impact Analysis

An attacker could exploit this to gain higher privileges on your system, potentially allowing them to install programs, view or delete data, or create new accounts with full user rights. Since it requires local authorization, physical or network access to the system may be needed.

Compliance Impact

This vulnerability could lead to unauthorized access or privilege escalation, which may violate compliance requirements for data protection standards like GDPR or HIPAA. Organizations might face penalties if such breaches occur due to unpatched systems.

Mitigation Strategies

Apply the latest security updates from Microsoft to patch the Windows DNS heap-based buffer overflow vulnerability. Monitor Microsoft's official update guide for patches and install them promptly.

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