CVE-2026-64533EPSS p7.5%
CVE-2026-64533CVE-2026-64533
Description
In the Linux kernel, the following vulnerability has been resolved:
fs/ntfs3: validate lcns_follow in log_replay conversion
log_replay() converts DIR_PAGE_ENTRY_32 records into DIR_PAGE_ENTRY
records when replaying version 0 restart tables.
During this conversion, the memmove() length is derived directly from
the on-disk lcns_follow field:
memmove(&dp->vcn, &dp0->vcn_low,
2 * sizeof(u64) +
le32_to_cpu(dp->lcns_follow) * sizeof(u64));
check_rstbl() validates restart table structure, but does not constrain
per-entry lcns_follow values relative to the entry size. A malformed
filesystem image can provide an oversized lcns_follow value, causing
the conversion memmove() to access memory beyond the bounds of the
allocated restart table buffer.
The same field is later used to bound iteration over page_lcns[],
so validating lcns_follow during conversion also prevents downstream
out-of-bounds access from the same malformed metadata.
Compute the maximum valid lcns_follow from the al
Scoring
| CVSS | 7.8 () |
| Vector | CVSS:3.1/AV:L/AC:L/PR:N/UI:R/S:U/C:H/I:H/A:H |
| EPSS | 0.19% probability of exploitation · percentile 7.5% · 2026-10-05T12:00:23Z |
| Last modified | 2026-08-17 |