CVE-2026-83565

Awaiting Analysis Awaiting Analysis - Queue

Buffer Over-Read in Windows Encrypting File System

Publication date: 2026-10-13

Last updated on: 2026-10-13

Assigner: Microsoft Corporation

Description

Buffer over-read in Windows Encrypting File System (EFS) allows an authorized attacker to disclose information locally.

CVSS Scores

EPSS Scores

Probability:
Percentile:

Meta Information

Published

2026-10-13

Last Modified

2026-10-13

Generated

2026-10-14

AI Q&A

2026-10-14

EPSS Evaluated

N/A

NVD

CVE-2026-83565

EUVD

EUVD-2026-99915

Affected Vendors & Products

Vendor	Product	Version / Range
Microsoft	Windows	10 Version 1607 10.0.14393.0
Microsoft	Windows	10 Version 1809 10.0.17763.0
Microsoft	Windows	10 Version 21H2 10.0.19044.0
Microsoft	Windows	10 Version 22H2 10.0.19045.0
Microsoft	Windows	11 version 23H2 10.0.22631.0
Microsoft	Windows	11 Version 23H2 10.0.22631.0
Microsoft	Windows	11 Version 24H2 10.0.26100.0
Microsoft	Windows	11 Version 25H2 10.0.26200.0
Microsoft	Windows	11 version 26H1 10.0.28000.0
Microsoft	Windows	11 Version 26H2 10.0.26300.0
Microsoft	Windows	Server 2016 10.0.14393.0
Microsoft	Windows	Server 2016 (Server Core installation) 10.0.14393.0
Microsoft	Windows	Server 2019 10.0.17763.0
Microsoft	Windows	Server 2019 (Server Core installation) 10.0.17763.0
Microsoft	Windows	Server 2022 10.0.20348.0
Microsoft	Windows	Server 2025 10.0.26100.0
Microsoft	Windows	Server 2025 (Server Core installation) 10.0.26100.0

Helpful Resources

Exploitability

CWE

KEV

CWE ID	Description
CWE-126	The product reads from a buffer using buffer access mechanisms such as indexes or pointers that reference memory locations after the targeted buffer.

Attack-Flow Graph

Executive Summary

This vulnerability is a buffer over-read in Windows Encrypting File System (EFS). It allows an authorized attacker to read beyond the intended buffer memory, potentially disclosing sensitive information stored locally on the system.

Impact Analysis

An attacker with local access could exploit this to read sensitive data, such as encrypted files or credentials, that should normally be protected by EFS. This could lead to unauthorized data disclosure or further attacks.

Compliance Impact

This vulnerability could violate compliance requirements that mandate protection of sensitive data, such as GDPR (data confidentiality) or HIPAA (protected health information). Unauthorized data disclosure may result in legal penalties or reputational damage.

Mitigation Strategies

Apply the latest Windows security updates from Microsoft to patch the EFS buffer over-read vulnerability. Disable EFS if not required and monitor for unusual file access patterns.

Hi! I’m here to help you understand CVE-2026-83565. Ask me anything about the vulnerability, its impact, or mitigation strategies.

0/70