NTFS-3G: Heap buffer overflow in index processing
Summary
NTFS-3G, a FUSE-based driver for reading and writing NTFS volumes, contains a heap buffer overflow in ntfs_index_walk_down() in libntfs-3g/index.c. The flaw affects the SUID-root ntfs-3g binary, so a local user who mounts a crafted NTFS image can corrupt heap memory. The vendor's CVSS v3.1 score is 8.1 (High), and the attack requires a local user to open or mount a malicious NTFS image.
Affected
- NTFS-3G before 2026.7.7 according to the CVE record.
- The GHSA advisory lists 2026.2.25 and earlier. Versions between 2026.2.25 and 2026.7.7 are unclear and should be treated as affected.
- Distribution packages may use backported versions.
Fixed in
- Upstream: NTFS-3G 2026.7.7 (July 15, 2026). Newer releases are also available, including 2026.9.18 and 2026.9.28.
- Backport patches exist for the 2022.10.3 and 2026.2.25 branches.
- Ubuntu: 26.04 (1:2022.10.3-5ubuntu1.1), 24.04 (1:2022.10.3-1.2ubuntu3.2), 22.04 (1:2021.8.22-3ubuntu1.4).
- Debian: 1:2026.7.7-1.
Workaround
Unknown. The vendor states that no known workarounds exist.
Exploitation
- No known exploitation in the wild.
- CISA SSVC: Exploitation none, Automatable no, Technical Impact total.
- No public proof of concept found.
- EPSS about 0.152%.
Our recommendation
- Update ntfs-3g to a fixed version from your distribution or to upstream 2026.7.7 or later.
- Until patched, do not mount NTFS volumes or images from untrusted sources.
- Remove ntfs-3g if it is not needed, or test the in-kernel ntfs3 driver for compatibility.
- Check Linux systems for SUID-root ntfs-3g binaries and restrict them where possible.
Public exploits
PoC-in-GitHub, Metasploit and Exploit-DB list nothing for this CVE.
Research sources
- GitHub Security Advisory GHSA-m6qq-pv5j-2wxc github.com
- NTFS-3G 2026.7.7 release github.com
- Ubuntu security notice CVE-2026-46570 ubuntu.com
- Debian review ntfs-3g dfsg-new-queue.debian.org
- OSV CVE-2026-46570 osv.dev
Researched and written up in English and German by an AI (Claude by Anthropic) based on NVD, CISA, EPSS and the sources listed. The vendor information is authoritative. Researched on 1 Nov 2026, 20:35.
Original description (NVD)
In NTFS-3G before 2026.7.7, a heap buffer overflow exists in ntfs_index_walk_down() in libntfs-3g/index.c that allows an attacker to corrupt heap memory in the SUID-root ntfs-3g binary by crafting a malicious NTFS image. The overflow is triggered by reading the special crafted file metadata.
Sources
The tracker combines official, freely usable data sources – updated continuously:
- NVD (NIST) – CVEs, rating (CVSS), affected products
- CISA KEV – vulnerabilities confirmed by CISA as actively exploited
- CISA Vulnrichment – CISA assessment (SSVC) in the official CVE record
- FIRST EPSS – probability of exploitation
- Microsoft MSRC – Patch Tuesday: vulnerabilities, severity, updates
- PoC-in-GitHub – public proof-of-concept repositories
- Metasploit (Rapid7) – modules of the Metasploit Framework
- Exploit-DB (OffSec) – archive of public exploits (links only)
- Patch days: official vendor pages (linked per vendor) (Vendor patch days)
This product uses data from the NVD API but is not endorsed or certified by the NVD. EPSS data © FIRST.org.
Affected? We can help.
We check whether your systems are affected, install updates and close the gap – continuously with the System Health Checker if you wish.