CVE-2026-89617: Linux Vulnerability (CVSS 7.8)

Description

In the Linux kernel, the following vulnerability has been resolved: fs/ntfs3: validate dirty page table on log replay Each DIR_PAGE_ENTRY ends in a page_lcns[] array whose length is the on-disk lcns_follow field. check_rstbl() validates the table bookkeeping but never checks that this array fits in the entry, so a crafted lcns_follow lets the v0->v1 conversion memmove and later replay passes run off the entry. Add check_dp_table() to reject, right after check_rstbl(), any entry larger than its size claims via struct_size() (the same expression used to allocate these entries, so the check is overflow-safe by construction). All consumers can then trust lcns_follow as the real capacity. This covers every page_lcns[] access whose index is bounded by the entry itself (the conversion memmove, the HotFix store via find_dp(), and the self-bounded scan loops). Accesses whose index comes from the log record need a separate bound and are handled in a follow-up patch.

Metrics

CVSS 3.1

7.8/10

CVSS:3.1/AV:L/AC:L/PR:L/UI:N/S:U/C:H/I:H/A:H

EPSS Probability

0.14%

3.5th percentile

Probability of exploitation in the next 30 days. Learn more

Affected Software

Source: CNA advisory (CVE.org). NVD analysis pending.

Vendor	Product	Versions
Linux	Linux	>= b46acd6a6a627d876898e1c84d3f84902264b445, < 0e07ea2fc45a7b4757ef7bf1f692cc0180a08323; >= b46acd6a6a627d876898e1c84d3f84902264b445, < 1e90b1703ee1a04cd3e9e399353fc536f5f3ba10; >= b46acd6a6a627d876898e1c84d3f84902264b445, < d23155634a4bc1183e761d5eb2c043b2e693cc98; >= b46acd6a6a627d876898e1c84d3f84902264b445, < 1200c2779c43b62656ccbb67df9468a7a9af2484; >= b46acd6a6a627d876898e1c84d3f84902264b445, < 2d94ffc9d7b5bb3517b129fe63b52d84bcd4ae56; >= b46acd6a6a627d876898e1c84d3f84902264b445, < 0908da07c23be4f94b99dfd9a94765525f0fe4bd; >= b46acd6a6a627d876898e1c84d3f84902264b445, < 006cb7713dec10368e699abc4367e5faa334c9a5
Linux	Linux	5.15

References

Timeline

Published: Sep 11, 2026
Last Modified: Sep 14, 2026
Status: Received

Frequently Asked Questions

What is CVE-2026-89617?

In the Linux kernel, the following vulnerability has been resolved: fs/ntfs3: validate dirty page table on log replay Each DIR_PAGE_ENTRY ends in a page_lcns[] array whose length is the on-disk lcns_follow field. check_rstbl() validates the table bookkeeping but never checks that this array fits in the entry, so a crafted lcns_follow lets the v0->v1 conversion memmove and later replay passes run off the entry. Add check_dp_table() to reject, right after check_rstbl(), any entry larger than its size claims via struct_size() (the same expression used to allocate these entries, so the check is overflow-safe by construction). All consumers can then trust lcns_follow as the real capacity. This covers every page_lcns[] access whose index is bounded by the entry itself (the conversion memmove, the HotFix store via find_dp(), and the self-bounded scan loops). Accesses whose index comes from the log record need a separate bound and are handled in a follow-up patch.

How severe is CVE-2026-89617?

CVE-2026-89617 has a CVSS score of 7.8/10 (HIGH severity). The EPSS model estimates a 0.14% probability of exploitation in the next 30 days.

How do I fix CVE-2026-89617?

Check the vendor references and advisories linked above for patched versions and mitigation guidance. You can also run a Strix scan to test if your systems are affected.

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