# CVE-2026-56135: NTFS-3G heap buffer overflow in build_inherited_id()

Source: https://junglewise.ai/threats/cve-2026-56135-ntfs-3g-heap-buffer-overflow-in-build-inherited-id  
Publisher: Junglewise Threat Intelligence, https://junglewise.ai/threats  
Published: 2026-08-24. Updated: 2026-09-25  
License: CC BY 4.0 with a link back

CVE-2026-56135 · Severity: high · CVSS 7.4 · Published 2026-08-24

NTFS-3G is a widely-used open-source driver that allows Linux and other operating systems to read and write NTFS-formatted storage devices. A heap buffer overflow vulnerability in the security.c module allows an attacker who can craft a malicious NTFS filesystem image to corrupt the memory of the SUID-root ntfs-3g binary, potentially leading to privilege escalation or denial of service. This vulnerability only affects systems that mount NTFS filesystems with the "inherit" option enabled, which is not the default configuration.

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

## Quick answers

**Is CVE-2026-56135 exploited in the wild?** No. Junglewise Threat Intelligence has no report of CVE-2026-56135 being exploited in the wild.

**How severe is CVE-2026-56135?** High severity, with a CVSS score of 7.4, published 24 August 2026.

**Which products and versions are affected?** Tuxera NTFS-3G through 2026.2.25.

**Is there a fix for CVE-2026-56135?** A patch was published on 2026-07-07: NTFS-3G version 2026.7.7 released with fix Junglewise finds every place you run it, drafts the upgrade and applies it once you approve.

**How is CVE-2026-56135 attacked?** It is attacked with local access.

**Am I affected by CVE-2026-56135?** 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.

## Technical details

The vulnerability is a heap-based buffer overflow in the build_inherited_id() function located in libntfs-3g/security.c. It is triggered when a file is created within a specially crafted directory on a malicious NTFS image. The attack vector is local, requiring an attacker to provide a crafted NTFS filesystem image (e.g., via USB drive), and the attack complexity is high because the "inherit" mount option must be explicitly enabled. An attacker with no prior privileges can exploit this to corrupt heap memory in the SUID-root ntfs-3g binary, potentially achieving code execution with root privileges. Patches are available in ntfs-3g versions 2022.10.3 (with backport patch) and 2026.7.7 (full fix).

## Affected products

- Tuxera NTFS-3G through 2026.2.25

## Timeline

- 2026-07-15: disclosed: GitHub security advisory published
- 2026-08-24: advisory: NVD entry published
- 2026-07-07: patched: NTFS-3G version 2026.7.7 released with fix

## References

- [https://github.com/tuxera/ntfs-3g/security/advisories/GHSA-c9qg-fh4v-mq8r](https://github.com/tuxera/ntfs-3g/security/advisories/GHSA-c9qg-fh4v-mq8r)

## Related threats

- [NTFS-3G heap buffer overflow in ntfscat](https://junglewise.ai/threats/cve-2026-42616-in-ntfs-3g-before-2026-7-7-a-heap-buffer-overflow-exists-in-cat)
- [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)