# CVE-2026-69463: Microsoft Windows NTFS heap-based buffer overflow

Source: https://junglewise.ai/threats/cve-2026-69463-microsoft-windows-ntfs-heap-based-buffer-overflow  
Publisher: Junglewise Threat Intelligence, https://junglewise.ai/threats  
Published: 2026-09-08. Updated: 2026-09-26  
License: CC BY 4.0 with a link back

CVE-2026-69463 · Severity: critical · CVSS 9.8 · Published 2026-09-08

Windows NTFS is the default file system that manages all data storage on Windows computers. A heap-based buffer overflow vulnerability allows an attacker on a network to execute arbitrary code on vulnerable systems, potentially leading to complete system compromise, data theft, or ransomware deployment.

Technologies: [Microsoft Windows NTFS](https://junglewise.ai/threats/technologies/windows-ntfs). Vendors: [Microsoft](https://junglewise.ai/threats/vendors/microsoft).

## Quick answers

**Is CVE-2026-69463 exploited in the wild?** No. Junglewise Threat Intelligence has no report of CVE-2026-69463 being exploited in the wild.

**How severe is CVE-2026-69463?** Critical severity, with a CVSS score of 9.8, published 8 September 2026.

**Which products and versions are affected?** Microsoft Windows NTFS <UNKNOWN>.

**Is there a fix for CVE-2026-69463?** 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-2026-69463 attacked?** It is attacked over the network.

**Am I affected by CVE-2026-69463?** Check whether you run Microsoft Windows NTFS 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 is a heap-based buffer overflow vulnerability in the Windows NTFS file system implementation. The vulnerability is remotely exploitable over a network without requiring authentication or user interaction. An attacker can craft a malicious network packet or file system operation to trigger the buffer overflow, leading to arbitrary code execution with the privileges of the NTFS driver (typically kernel-level). The attack vector is network-based, making this a wormable vulnerability with high attack surface. Microsoft has released security updates to address this issue.

## Affected products

- Microsoft Windows NTFS <UNKNOWN>

## Timeline

- 2026-09-08: disclosed

## References

- [https://msrc.microsoft.com/update-guide/vulnerability/CVE-2026-69463](https://msrc.microsoft.com/update-guide/vulnerability/CVE-2026-69463)

## Related threats

- [Windows NTFS pointer dereference remote code execution](https://junglewise.ai/threats/cve-2026-105542-untrusted-pointer-dereference-in-windows-ntfs-allows-an)
- [Windows NTFS improper access control information disclosure](https://junglewise.ai/threats/cve-2026-83864-improper-access-control-in-windows-ntfs-allows-an-authorized)
- [Windows NTFS format string privilege elevation](https://junglewise.ai/threats/cve-2026-83585-use-of-externally-controlled-format-string-in-windows-ntfs-allows)
- [Windows NTFS out-of-bounds read privilege escalation](https://junglewise.ai/threats/cve-2026-83508-out-of-bounds-read-in-windows-ntfs-allows-an-authorized-attacker)
- [Windows NTFS integer overflow allows privilege escalation](https://junglewise.ai/threats/cve-2026-69916-integer-overflow-or-wraparound-in-windows-ntfs-allows-an)