CVE-2026-98135
In the Linux kernel, the following vulnerability has been resolved: ntfs: reject invalid sectors_per_cluster in the boot sector is_boot_sector_ntfs() checks the boot sector's sectors_per_cluster field with a range test that rejects 0x81..0xf3 but accepts 0 and other non-power-of-two counts. A zero value reaches parse_ntfs_boot_sector(): sectors_per_cluster_bits = ffs(sectors_per_cluster) - 1; ... vol->cluster_size = vol->sector_size << sectors_per_cluster_bits; ffs(0) is 0, so sectors_per_cluster_bits becomes (unsigned)-1 and the shift is undefined: UBSAN: shift-out-of-bounds in fs/ntfs/super.c:673:39 shift exponent 4294967295 is too large for 32-bit type 'int' This change rejects any non-power-of-two value, since it feeds the aforementioned shift via ffs() - 1, which only yields the correct shift for a power of two.
Affected versions
Linux kernel versions
7.1
and later are affected. Fixed in
7.2.7,
7.3-rc2
and their respective stable series.
References
2 totalFrequently asked questions
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What is CVE-2026-98135?
CVE-2026-98135 is a unscored severity Linux kernel vulnerability . It affects Linux kernel versions from 7.1 onward and has been patched in 7.2.7 and 7.3-rc2. CVE-2026-98135 has not been confirmed as actively exploited and is not listed in the CISA KEV catalog.
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Is there a patch available for CVE-2026-98135?
Yes. CVE-2026-98135 has been patched. Fixed versions include 7.2.7 and 7.3-rc2. If you are running Linux kernel 7.1 or later up to the fix versions, apply the relevant patch for your kernel branch.
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Is CVE-2026-98135 actively exploited?
No. CVE-2026-98135 has not been confirmed as actively exploited. It is not listed in the CISA Known Exploited Vulnerabilities (KEV) catalog.