CVE-2026-49172: Microsoft Windows FTP Service heap overflow remote code execution

CVE-2026-49172 · Severity: critical · CVSS 9.8 · Published 2026-07-14

A critical vulnerability has been identified in the Windows FTP Service, a component used for transferring files over a network. An unauthorized attacker can exploit this flaw remotely to take full control of the affected system without any user interaction. This could lead to the theft of sensitive data, service disruptions, or the installation of malicious software across the corporate network.

Technologies: Microsoft Windows 11, Microsoft Windows 10. Vendors: Microsoft.

Quick answers

Is CVE-2026-49172 exploited in the wild?
No. Junglewise Threat Intelligence has no report of CVE-2026-49172 being exploited in the wild.
How severe is CVE-2026-49172?
Critical severity, with a CVSS score of 9.8, published 14 July 2026.
Which products and versions are affected?
Microsoft Windows 11 10.0.22631.0 to 10.0.22631.7376; Microsoft Windows 10 10.0.14393.0 to 10.0.14393.9339.
Is there a fix for CVE-2026-49172?
No fixed version is recorded yet. Check the vendor's advisory in the references below. If you run it, Junglewise drafts a mitigation that fits your setup and applies it once you approve, with senior security engineers behind it.
How is CVE-2026-49172 attacked?
It is attacked over the network, in an operating system.
Am I affected by CVE-2026-49172?
Check whether you run Microsoft Windows 11 or Microsoft Windows 10 at an affected version. Junglewise does that check for you around the clock: connect your code, cloud and domains, and it matches new vulnerabilities like this one against what you actually run and tells you when one reaches you.

Technical details

This vulnerability is a heap-based buffer overflow (CWE-122) residing within the Windows FTP Service. The flaw can be triggered by a remote, unauthenticated attacker sending specially crafted packets over the network to a system running the affected service. Successful exploitation allows for remote code execution (RCE) in the context of the service. The vulnerability affects multiple versions of Windows 10 and Windows 11. Microsoft has released security updates to address this issue, and users are advised to apply the latest patches from the MSRC Update Guide.

Affected products

  • Microsoft Windows 10 Version 1607 10.0.14393.0 to 10.0.14393.9339
  • Microsoft Windows 10 Version 1809 10.0.17763.0 to 10.0.17763.9020
  • Microsoft Windows 10 Version 21H2 10.0.19044.0 to 10.0.19044.7548
  • Microsoft Windows 10 Version 22H2 10.0.19045.0 to 10.0.19045.7548
  • Microsoft Windows 11 Version 23H2 10.0.22631.0 to 10.0.22631.7376
  • Microsoft Windows 11 Version 24H2 10.0.26100.0 to 10.0.26100.8875
  • Microsoft Windows 11 Version 25H2 10.0.26200.0 to 10.0.26200.8875
  • Microsoft Windows 11 Version 26H1 10.0.28000.0 to 10.0.28000.2269

Timeline

  • 2026-07-14: disclosed
  • 2026-07-14: advisory

References

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