CVE-2026-70347

Analyzed Analyzed - Analysis Complete

Heap-based Buffer Overflow in Windows Installer

Publication date: 2026-08-11

Last updated on: 2026-08-16

Assigner: Microsoft Corporation

Description

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

CVSS Scores

EPSS Scores

Probability:
Percentile:

Meta Information

Published

2026-08-11

Last Modified

2026-08-16

Generated

2026-09-01

AI Q&A

2026-08-12

EPSS Evaluated

2026-08-30

NVD

CVE-2026-70347

EUVD

EUVD-2026-56599

Affected Vendors & Products

Vendor	Product	Version / Range
microsoft	windows_server_2012	r2
microsoft	windows_10_1607	to 10.0.14393.9418 (exc)
microsoft	windows_10_1607	to 10.0.14393.9418 (exc)
microsoft	windows_10_1809	to 10.0.17763.9115 (exc)
microsoft	windows_10_1809	to 10.0.17763.9115 (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_2019	to 10.0.17763.9115 (exc)
microsoft	windows_server_2022	to 10.0.20348.5440 (exc)
microsoft	windows_server_2025	to 10.0.26100.33222 (exc)
microsoft	windows_server_2012	to 6.2.9200.26280 (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 Installer. An authorized attacker can exploit it to elevate their privileges locally on an affected system.

Detection Guidance

This vulnerability involves a heap-based buffer overflow in Windows Installer. Detection typically requires monitoring for unusual privilege escalation events or crashes in Windows Installer processes. Check Windows Event Logs for installer-related errors or application crashes. Use commands like 'wevtutil qe System /q:"<EventID>"' to query logs for installer failures.

Impact Analysis

An attacker with local access could exploit this to gain higher privileges, potentially allowing them to install programs, view or delete data, or create new accounts with full user rights.

Compliance Impact

This vulnerability could lead to unauthorized privilege escalation, potentially violating data protection requirements under GDPR or HIPAA by allowing unauthorized access to sensitive information.

Mitigation Strategies

Apply the latest security updates from Microsoft as soon as possible to patch the heap-based buffer overflow in Windows Installer. Monitor Microsoft's update guide for the official patch.

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