CVE-2026-72478
HighCVSS 8.4Exploitation Probability (EPSS)
Low risk5th percentile - higher than 5% of all known CVEs
Summary
In the Linux kernel, the NTFS3 filesystem has an out-of-bounds read vulnerability in run_get_highest_vcn(). The function parses a packed mapping-pairs buffer without any length bound, relying solely on a 0x00 terminator. A crafted $LogFile UpdateMappingPairs record can cause a read past the slab allocation, triggering a KASAN error during mount. The fix adds a run_buf_size parameter and rejects run headers whose payload would extend past the buffer end.
Risk Assessment
The vulnerability can lead to system crash when mounting a malicious NTFS volume, which could be exploited by an attacker with physical access to the disk or remotely if the file is shared.
Recommendation
Apply the patch from the Linux kernel that adds bounds checking in run_get_highest_vcn(). Update the kernel to a patched version.
Original NVD description (English source)
In the Linux kernel, the following vulnerability has been resolved: fs/ntfs3: add bounds check to run_get_highest_vcn() run_get_highest_vcn() parses a packed NTFS mapping-pairs buffer without any length bound, relying solely on a 0x00 terminator to stop. A crafted $LogFile UpdateMappingPairs record whose embedded attribute contains mapping-pairs runs without a terminator causes the function to read past the slab allocation, triggering a KASAN slab-out-of-bounds read on mount. The sibling function run_unpack() received an analogous bounds-check in commit b62567bca474 ("ntfs3: add buffer boundary checks to run_unpack()"), but run_get_highest_vcn() was missed. Take a run_buf_size parameter and reject any run header whose payload would extend past the buffer end, mirroring the pattern used by run_unpack(). The caller in fslog.c passes the remaining attribute bytes after the mapping-pairs offset. KASAN report (on mainline v7.1 merge window HEAD): BUG: KASAN: slab-out-of-bounds in run_get_highest_vcn+0x3c0/0x410 Read of size 1 at addr ffff88800e2d5400 by task mount/72 Call Trace: run_get_highest_vcn+0x3c0/0x410 do_action.isra.0+0x3ba8/0x7b50 log_replay+0x9ddd/0x10200 ntfs_loadlog_and_replay+0x4ad/0x610 ntfs_fill_super+0x214a/0x4540