CVE-2026-40706

NTFS-3G is a stable, open source, GPL licensed, POSIX, read/write NTFS driver for Linux and many other operating systems. It provides safe handling of the Windows XP, Windows Server 2003, Windows 2000, Windows Vista, Windows Server 2008 and Windows 7 NTFS file systems.

Security Fix(es):

A heap buffer overflow exists in ntfs_build_permissions_posix() (acls.c:4011-4027) 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.

The overflow size is attacker-controlled (8 to 14,000+ bytes) and writes partially attacker-controlled data (POSIX_ACE entries with attacker-derived GID values) past the heap allocation. This corrupts adjacent glibc heap chunk metadata, as confirmed by a crash in _int_free() with "free(): corrupted unsorted chunks".(CVE-2026-40706)

NTFS-3G is a stable, open source, GPL licensed, POSIX, read/write NTFS driver for Linux and many other operating systems. It provides safe handling of the Windows XP, Windows Server 2003, Windows 2000, Windows Vista, Windows Server 2008 and Windows 7 NTFS file systems.

Security Fix(es):

A heap buffer overflow exists in ntfs_build_permissions_posix() (acls.c:4011-4027) 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.

The overflow size is attacker-controlled (8 to 14,000+ bytes) and writes partially attacker-controlled data (POSIX_ACE entries with attacker-derived GID values) past the heap allocation. This corrupts adjacent glibc heap chunk metadata, as confirmed by a crash in _int_free() with "free(): corrupted unsorted chunks".(CVE-2026-40706)

NTFS-3G is a stable, open source, GPL licensed, POSIX, read/write NTFS driver for Linux and many other operating systems. It provides safe handling of the Windows XP, Windows Server 2003, Windows 2000, Windows Vista, Windows Server 2008 and Windows 7 NTFS file systems.

Security Fix(es):

A heap buffer overflow exists in ntfs_build_permissions_posix() (acls.c:4011-4027) 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.

The overflow size is attacker-controlled (8 to 14,000+ bytes) and writes partially attacker-controlled data (POSIX_ACE entries with attacker-derived GID values) past the heap allocation. This corrupts adjacent glibc heap chunk metadata, as confirmed by a crash in _int_free() with "free(): corrupted unsorted chunks".(CVE-2026-40706)

NTFS-3G is a stable, open source, GPL licensed, POSIX, read/write NTFS driver for Linux and many other operating systems. It provides safe handling of the Windows XP, Windows Server 2003, Windows 2000, Windows Vista, Windows Server 2008 and Windows 7 NTFS file systems.

Security Fix(es):

A heap buffer overflow exists in ntfs_build_permissions_posix() (acls.c:4011-4027) 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.

The overflow size is attacker-controlled (8 to 14,000+ bytes) and writes partially attacker-controlled data (POSIX_ACE entries with attacker-derived GID values) past the heap allocation. This corrupts adjacent glibc heap chunk metadata, as confirmed by a crash in _int_free() with "free(): corrupted unsorted chunks".(CVE-2026-40706)

NTFS-3G is a stable, open source, GPL licensed, POSIX, read/write NTFS driver for Linux and many other operating systems. It provides safe handling of the Windows XP, Windows Server 2003, Windows 2000, Windows Vista, Windows Server 2008 and Windows 7 NTFS file systems.

Security Fix(es):

A heap buffer overflow exists in ntfs_build_permissions_posix() (acls.c:4011-4027) 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.

The overflow size is attacker-controlled (8 to 14,000+ bytes) and writes partially attacker-controlled data (POSIX_ACE entries with attacker-derived GID values) past the heap allocation. This corrupts adjacent glibc heap chunk metadata, as confirmed by a crash in _int_free() with "free(): corrupted unsorted chunks".(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.

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.

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. (CVE-2026-40706)

These are all security issues fixed in the libntfs-3g-devel-2022.10.3-6.1 package on the GA media of openSUSE Tumbleweed.

This update for ntfs-3g_ntfsprogs fixes the following issue:

• CVE-2026-40706: heap buffer overflow in ntfs_build_permissions_posix() in acls.c (bsc#1262216).

This update for ntfs-3g_ntfsprogs fixes the following issue:

• CVE-2026-40706: heap buffer overflow in ntfs_build_permissions_posix() in acls.c (bsc#1262216).

This update for ntfs-3g_ntfsprogs fixes the following issue:

• CVE-2026-40706: heap buffer overflow in ntfs_build_permissions_posix() in acls.c (bsc#1262216).

Jeffrey Bencteux discovered that NTFS-3G incorrectly handled certain UTF-8 sequences. An attacker could use this issue to cause NTFS-3G to crash, resulting in a denial of service, or to execute arbitrary code. This issue only affected Ubuntu 22.04 LTS and Ubuntu 24.04 LTS. (CVE-2023-52890)

Andrea Bocchetti discovered that NTFS-3G incorrectly handled certain security descriptors. An attacker could use this issue to cause NTFS-3G to crash, resulting in a denial of service, or to execute arbitrary code. (CVE-2026-40706)

USN-8192-1 fixed vulnerabilities in NTFS-3G. This update provides the corresponding update to Ubuntu 26.04 LTS.

Original advisory details:

Jeffrey Bencteux discovered that NTFS-3G incorrectly handled certain UTF-8 sequences. An attacker could use this issue to cause NTFS-3G to crash, resulting in a denial of service, or to execute arbitrary code. This issue only affected Ubuntu 22.04 LTS and Ubuntu 24.04 LTS. (CVE-2023-52890)

Andrea Bocchetti discovered that NTFS-3G incorrectly handled certain security descriptors. An attacker could use this issue to cause NTFS-3G to crash, resulting in a denial of service, or to execute arbitrary code. (CVE-2026-40706)