CVE-2026-49172: Windows FTP Service Remote Code Execution Vulnerability

Overview

Severity: Critical (CVSS 9.8)
CVSS Vector: CVSS:3.1/AV:N/AC:L/PR:N/UI:N/S:U/C:H/I:H/A:H/E:U/RL:O/RC:C
Category: Remote Code Execution
Exploit Status: Not Exploited
Exploitation Likelihood: Less Likely
Patch Tuesday: 2026-Jul
Released: 2026-07-14

Description

Heap-based buffer overflow in Windows FTP Service allows an unauthorized attacker to execute code over a network.

FAQ

How could an attacker exploit this vulnerability? An attacker could exploit this vulnerability by sending specially crafted FTP commands that exceed the expected length to a vulnerable FTP service. When the service processes and logs these oversized commands, it may write beyond the bounds of allocated memory, causing memory corruption that could lead to a service crash or allow code execution.

Affected Products (23)

Windows

Windows 11 Version 25H2 for x64-based Systems
Windows Server 2025
Windows 10 Version 21H2 for ARM64-based Systems
Windows Server 2022 (Server Core installation)
Windows 10 Version 1809 for 32-bit Systems
Windows 11 Version 23H2 for ARM64-based Systems
Windows 11 Version 25H2 for ARM64-based Systems
Windows 11 Version 24H2 for ARM64-based Systems
Windows 10 Version 1607 for 32-bit Systems
Windows Server 2022
Windows 11 Version 23H2 for x64-based Systems
Windows 11 version 26H1 for x64-based Systems
Windows 11 Version 26H1 for ARM64-based Systems
Windows 10 Version 21H2 for x64-based Systems
Windows Server 2019 (Server Core installation)
Windows Server 2025 (Server Core installation)
Windows 11 Version 24H2 for x64-based Systems
Windows 10 Version 21H2 for 32-bit Systems
Windows Server 2019
Windows 10 Version 1809 for x64-based Systems

ESU

Windows 10 Version 22H2 for ARM64-based Systems
Windows 10 Version 22H2 for x64-based Systems
Windows 10 Version 22H2 for 32-bit Systems

Security Updates (9)

Acknowledgments

Linzishan & Anemone& Zhiniang Peng (HUST)

Revision History

2026-07-14: Information published.