CVE-2026-40706
Severity CVSS v4.0:
Pending analysis
Type:
CWE-122
Heap-based Buffer Overflow
Publication date:
21/04/2026
Last modified:
22/04/2026
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.
Impact
Base Score 3.x
8.40
Severity 3.x
HIGH
References to Advisories, Solutions, and Tools
- https://github.com/tuxera/ntfs-3g/blob/d3ace19838ce37cfde55294e76841e6d2f393f9e/libntfs-3g/acls.c#L4011-L4027
- https://github.com/tuxera/ntfs-3g/releases/tag/2026.2.25
- https://github.com/tuxera/ntfs-3g/security/advisories/GHSA-4cwv-5285-63v9
- https://www.openwall.com/lists/oss-security/2026/04/21/4
- http://www.openwall.com/lists/oss-security/2026/04/21/4
- https://lists.debian.org/debian-lts-announce/2026/04/msg00024.html



