# CVE-2026-42616: NTFS-3G heap buffer overflow in ntfscat

Source: https://junglewise.ai/threats/cve-2026-42616-in-ntfs-3g-before-2026-7-7-a-heap-buffer-overflow-exists-in-cat  
Publisher: Junglewise Threat Intelligence, https://junglewise.ai/threats  
Published: 2026-10-07. Updated: 2026-10-19  
License: CC BY 4.0 with a link back

CVE-2026-42616 · Severity: high · CVSS 7.8 · Published 2026-10-07

NTFS-3G is a toolkit for reading and writing NTFS filesystem images. A heap buffer overflow in the ntfscat utility allows an attacker who can provide a malicious NTFS image to corrupt memory and potentially execute code with the privileges of the user running ntfscat. Exploitation requires the attacker to craft a malicious filesystem image and have a user read a file from it.

Technologies: [Tuxera NTFS-3G](https://junglewise.ai/threats/technologies/ntfs-3g). Vendors: [Tuxera](https://junglewise.ai/threats/vendors/tuxera).

## Quick answers

**Is CVE-2026-42616 exploited in the wild?** No. Junglewise Threat Intelligence has no report of CVE-2026-42616 being exploited in the wild.

**How severe is CVE-2026-42616?** High severity, with a CVSS score of 7.8, published 7 October 2026.

**Which products and versions are affected?** Tuxera NTFS-3G before 2026.7.7.

**Is there a fix for CVE-2026-42616?** Yes: fixed in 2026.7.7. Until then: Do not use ntfscat as superuser. Avoid processing untrusted or maliciously crafted NTFS filesystem images with ntfscat until patching. Junglewise finds every place you run it, drafts the upgrade and applies it once you approve.

**How is CVE-2026-42616 attacked?** It is attacked with local access, in a software library.

**Am I affected by CVE-2026-42616?** Check whether you run Tuxera NTFS-3G 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.

## How to fix

- Fixed in 2026.7.7

Do not use ntfscat as superuser. Avoid processing untrusted or maliciously crafted NTFS filesystem images with ntfscat until patching.

## Technical details

A heap buffer overflow exists in the cat() function in ntfscat.c that is triggered when reading a file from a crafted NTFS image. The vulnerability allows an attacker to write out-of-bounds on the heap, corrupting memory and potentially achieving code execution. Exploitation requires local access (a malicious filesystem image) and user interaction (the user must read a file), but does not require elevated privileges.

## Affected products

- Tuxera NTFS-3G before 2026.7.7

## Timeline

- 2026-07-15: disclosed
- 2026-07-15: patched: Version 2026.7.7 released

## References

- [https://github.com/tuxera/ntfs-3g/releases](https://github.com/tuxera/ntfs-3g/releases)
- [https://github.com/tuxera/ntfs-3g/security/advisories/GHSA-p6mp-gp2j-7358](https://github.com/tuxera/ntfs-3g/security/advisories/GHSA-p6mp-gp2j-7358)

## Related threats

- [NTFS-3G out-of-bounds read in ntfs_ir_nill()](https://junglewise.ai/threats/cve-2026-56136-ntfs-3g-out-of-bounds-read-in-ntfs-ir-nill)
- [NTFS-3G heap buffer overflow in build_inherited_id()](https://junglewise.ai/threats/cve-2026-56135-ntfs-3g-heap-buffer-overflow-in-build-inherited-id)