CVE-2026-40706

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.

CVSS 3.1

8.4CVSS:3.1/AV:L/AC:L/PR:N/UI:N/S:U/C:H/I:H/A:H

EPSS

0.2% chance of exploitation in the next 30 days; higher than 5% of CVEs (scores of 2026-10-26)

CWE

CWE-122

Published

2026-04-21

Modified

2026-10-26

Record from

the NVD, synced 2026-10-26

References

• 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

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