CVE-2026-89615 fs/ntfs3: bound page_lcns[] index by the log record

What is CVE-2026-89615?

CVE-2026-89615 is a high-severity memory corruption vulnerability in Linux, published on 11 Sep 2026. It can only be exploited from the same machine or local network, with no action from the victim.

Official description

In the Linux kernel, the following vulnerability has been resolved:

fs/ntfs3: bound page_lcns[] index by the log record

The copy_lcns loop and the redo shorten loop index page_lcns[] at j + i, where i runs up to the log record's lcns_follow. That count is checked only against the record's own length, not the target entry, so check_dp_table() (which validates the entry's lcns_follow) does not cover it: the copy_lcns entry may even be freshly allocated after that check, and find_dp() bounds j but not i. A crafted record thus overflows page_lcns[] of an otherwise valid entry.

Add dp_range_ok() and reject, before each loop, any record whose run does not fit the entry. These are the only two page_lcns[] accesses indexed by the record rather than the entry, so together with the entry validation every access is now bounded.

[[email protected]: original patch contained changes to the problem already handled, applied partly]

Which versions are affected by CVE-2026-89615?

How do I fix CVE-2026-89615?

Apply the vendor's patch.

Upgrade to the fixed version. Memory-safe languages, compiler hardening and fuzzing prevent most new cases. More about Memory corruption.

Is CVE-2026-89615 being exploited?

There is no known exploitation of CVE-2026-89615 in the wild and no public exploit code.

Sources

• CVE record
• NVD
• OSV
• GitHub advisory
• How this page is made

Also known as AZL-100625, BELL-CVE-2026-89615, DEBIAN-CVE-2026-89615, GHSA-r33c-hmhm-vc95, UBUNTU-CVE-2026-89615.