Junglewise Threat Intelligence

CVE-2026-31716: Linux Kernel NTFS3 out-of-bounds write in journal replay

CVE-2026-31716 · Severity: high · CVSS 7.8 · Published 2026-05-01

Technologies: Linux Kernel. Vendors: Linux.

Executive brief

A vulnerability in the Linux kernel's NTFS3 file system driver could allow a system crash or memory corruption when processing a specially crafted or corrupted NTFS disk image. This occurs during the 'journal replay' process, which is a standard recovery step when mounting a disk. An attacker could potentially exploit this by tricking a user or system into mounting a malicious drive or partition, leading to a complete system compromise.

Technical details

An out-of-bounds write vulnerability (CWE-787) exists in the fs/ntfs3/fslog.c component of the Linux kernel. The function check_file_record() fails to validate the 'rec->used' field against the record size or attribute offsets. During journal replay, the do_action() handlers use this unvalidated value to calculate lengths for memmove operations (e.g., DeleteAttribute, CreateAttribute). If 'rec->used' is smaller than the attribute offset, an integer underflow occurs, resulting in massive memory copies into a fixed 4KB buffer. This can be triggered by a corrupted or malicious NTFS filesystem. Patches have been released across multiple stable kernel branches to bound 'rec->used' correctly.

Affected products

  • Linux Linux Kernel 5.15 to 6.6.136, 6.7 to 6.12.84, 6.13 to 6.18.25, 6.19 to 7.0.2

Timeline

  • 2026-05-01: advisory: Initial disclosure and NVD publication
  • 2026-04-09: patched: Fix authored by Greg Kroah-Hartman

References