CVE-2026-89612: kernel: Linux kernel: Out-of-bounds memory access in NTFS via crafted boot sector

Severity: Critical

CVSS Score: 9.8

In the Linux kernel, the following vulnerability has been resolved: ntfs: reject invalid MFT LCNs from boot sector The NTFS boot sector stores the MFT and MFTMirr locations as unsigned 64-bit LCNs, but parse_ntfs_boot_sector() decoded them into an s64. A crafted high-bit value could therefore become negative and pass the existing upper-bound check. The invalid value then propagated into the MFT zone allocator and could result in an out-of-bounds access to lcn_empty_bits_per_page.