Vulnerability · Published Apr 21, 2026 · Assigned by mitre
CVE-2026-40706
High 8.4
In plain English
A high-severity heap buffer overflow in NTFS-3G from Tuxera. There are no confirmed reports of exploitation so far. The chance it is exploited in the next 30 days is estimated at 0.2% (higher than 6% of all known vulnerabilities). Fixed versions are available - upgrade the affected package.
Official description
In NTFS-3G 2022.10.3 before 2026.2.25, a heap buffer overflow exists in ntfs_build_permissions_posix() in acls.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 on the READ path (stat, readdir, open) when processing a security descriptor with multiple ACCESS_DENIED ACEs containing WRITE_OWNER from distinct group SIDs.
Affected packages & fixed versions
| Ecosystem | Package | Fixed in | Advisory |
|---|---|---|---|
| Alpine:v3.20 | ntfs-3g | 2026.2.25-r0 | ALPINE-CVE-2026-40706 |
| Alpine:v3.21 | ntfs-3g | 2026.2.25-r0 | ALPINE-CVE-2026-40706 |
| Alpine:v3.22 | ntfs-3g | 2026.2.25-r0 | ALPINE-CVE-2026-40706 |
| Alpine:v3.23 | ntfs-3g | 2026.2.25-r0 | ALPINE-CVE-2026-40706 |
| Alpine:v3.24 | ntfs-3g | 2026.2.25-r0 | ALPINE-CVE-2026-40706 |
| Debian:12 | ntfs-3g | 1:2022.10.3-1+deb12u3 | DEBIAN-CVE-2026-40706 |
| Debian:13 | ntfs-3g | 1:2022.10.3-5+deb13u1 | DEBIAN-CVE-2026-40706 |
| Debian:14 | ntfs-3g | 1:2026.2.25-1 | DEBIAN-CVE-2026-40706 |
| Ubuntu:22.04:LTS | ntfs-3g | 1:2021.8.22-3ubuntu1.3 | USN-8192-1 |
| Ubuntu:22.04:LTS | ntfs-3g | 1:2021.8.22-3ubuntu1.3 | UBUNTU-CVE-2026-40706 |
| Ubuntu:24.04:LTS | ntfs-3g | 1:2022.10.3-1.2ubuntu3.1 | USN-8192-1 |
| Ubuntu:24.04:LTS | ntfs-3g | 1:2022.10.3-1.2ubuntu3.1 | UBUNTU-CVE-2026-40706 |
| Ubuntu:25.10 | ntfs-3g | 1:2022.10.3-5ubuntu0.25.10.1 | UBUNTU-CVE-2026-40706 |
| Ubuntu:25.10 | ntfs-3g | 1:2022.10.3-5ubuntu0.25.10.1 | USN-8192-1 |
| Ubuntu:26.04:LTS | ntfs-3g | 1:2022.10.3-5ubuntu1 | UBUNTU-CVE-2026-40706 |
Affected products (as reported)
Weakness: CWE-122 · Vector: CVSS:3.1/AV:L/AC:L/PR:N/UI:N/S:U/C:H/I:H/A:H
References
- https://github.com/tuxera/ntfs-3g/blob/d3ace19838ce37cfde55294e76841e6d2f393f9e/libntfs-3g/acls.c#L4011-L4027
- https://www.openwall.com/lists/oss-security/2026/04/21/4
- https://github.com/tuxera/ntfs-3g/security/advisories/GHSA-4cwv-5285-63v9
- https://github.com/tuxera/ntfs-3g/releases/tag/2026.2.25
- https://lists.debian.org/debian-lts-announce/2026/04/msg00024.html
- http://www.openwall.com/lists/oss-security/2026/04/21/4