CVE-2026-83871

Analyzed Analyzed - Analysis Complete

Heap-based Buffer Overflow in OpenSSH for Windows

Publication date: 2026-10-13

Last updated on: 2026-10-21

Assigner: Microsoft Corporation

Description

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

CVSS Scores

EPSS Scores

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Meta Information

Published

2026-10-13

Last Modified

2026-10-21

Generated

2026-11-08

AI Q&A

2026-10-14

EPSS Evaluated

2026-11-07

NVD

CVE-2026-83871

EUVD

EUVD-2026-99428

Affected Vendors & Products

Vendor	Product	Version / Range
microsoft	windows_server_2022	to 10.0.20348.5761 (exc)
microsoft	windows_10_1809	to 10.0.17763.9376 (exc)
microsoft	windows_10_1809	to 10.0.17763.9376 (exc)
microsoft	windows_10_21h2	to 10.0.19044.7807 (exc)
microsoft	windows_10_21h2	to 10.0.19044.7807 (exc)
microsoft	windows_10_21h2	to 10.0.19044.7807 (exc)
microsoft	windows_11_23h2	to 10.0.22631.7652 (exc)
microsoft	windows_11_23h2	to 10.0.22631.7652 (exc)
microsoft	windows_11_24h2	to 10.0.26100.9711 (exc)
microsoft	windows_11_24h2	to 10.0.26100.9711 (exc)
microsoft	windows_11_25h2	to 10.0.26200.9711 (exc)
microsoft	windows_11_25h2	to 10.0.26200.9711 (exc)
microsoft	windows_11_26h1	to 10.0.28000.3231 (exc)
microsoft	windows_11_26h1	to 10.0.28000.3231 (exc)
microsoft	windows_11_26h2	to 10.0.26300.9711 (exc)
microsoft	windows_11_26h2	to 10.0.26300.9711 (exc)
microsoft	windows_server_2019	to 10.0.17763.9376 (exc)
microsoft	windows_server_2025	to 10.0.26100.33650 (exc)
microsoft	windows_10_22h2	to 10.0.19045.7807 (exc)
microsoft	windows_10_22h2	to 10.0.19045.7807 (exc)
microsoft	windows_10_22h2	to 10.0.19045.7807 (exc)

Helpful Resources

Exploitability

CWE

KEV

CWE ID	Description
CWE-367	The product checks the state of a resource before using that resource, but the resource's state can change between the check and the use in a way that invalidates the results of the check.
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 OpenSSH for Windows. It allows an authorized attacker with local access to escalate their privileges on the system.

Impact Analysis

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

Compliance Impact

This vulnerability allows local privilege escalation via heap-based buffer overflow in OpenSSH for Windows. Such unauthorized privilege elevation could lead to unauthorized access to sensitive data, violating confidentiality requirements in GDPR and HIPAA. Compliance may be impacted if systems storing regulated data are affected.

Mitigation Strategies

Apply the latest security updates from Microsoft for OpenSSH for Windows. Monitor Microsoft's update guide for patches and install them immediately to prevent exploitation.

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