CVE-2026-70116: Windows Resilient File System (ReFS) Security Feature Bypass Vulnerability

Overview

Severity

Medium (CVSS 4.2)

CVSS Vector

CVSS:3.1/AV:P/AC:H/PR:N/UI:N/S:U/C:N/I:H/A:N/E:U/RL:O/RC:C

Category

Security Feature Bypass

Exploit Status

Not Exploited

Exploitation Likelihood

Less Likely

Patch Tuesday

2026-Oct

Released

2026-10-13

Description

Stack-based buffer overflow in Windows Resilient File System (ReFS) allows an unauthorized attacker to bypass a security feature with a physical attack.

FAQ

According to the CVSS metric, the attack complexity is high (AC:H). What does that mean for this vulnerability? A high attack complexity means that successful exploitation is complex and time‑consuming, requiring significant effort and precise conditions for an attacker to reliably exploit the vulnerability.

Affected Products (10)

Windows

• Windows 11 Version 24H2 for ARM64-based Systems
• Windows 11 Version 24H2 for x64-based Systems
• Windows 11 Version 25H2 for x64-based Systems
• Windows 11 Version 26H2 for ARM64-based Systems
• Windows 11 Version 26H2 for x64-based Systems
• Windows Server 2025
• Windows Server 2025 (Server Core installation)
• Windows 11 Version 26H1 for ARM64-based Systems
• Windows 11 version 26H1 for x64-based Systems
• Windows 11 Version 25H2 for ARM64-based Systems

Security Updates (3)

• 5127648
• 5126646
• 5127646

Acknowledgments

<a href="https://github.com/0x00000ff">Kangjun Heo</a> with <a href="https://plus.cnu.ac.kr/">Chungnam National University</a>

Revision History

• 2026-10-13: Information published.