CVE-2026-68083 ksmbd: fix path resolution in ksmbd_vfs_kern_path_create
An authenticated attacker can escape the SMB share directory via a race condition in path resolution, allowing unauthorized file access or modification.
- Exploited in the wild
- Not known
- Login needed
- Not needed
- Attackable
- Over the internet
- Victim action needed
- Not needed
- Fix
- Available
What is CVE-2026-68083?
CVE-2026-68083 is a critical path traversal vulnerability in Linux, published on 10 Aug 2026. An attacker can exploit it over the internet without logging in, with no action from the victim.
Official 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.
Which versions are affected by CVE-2026-68083?
How do I fix CVE-2026-68083?
Apply the vendor's patch.
Upgrade, and resolve every user-supplied path against an allowed base folder before opening it. More about Path traversal.
Is CVE-2026-68083 being exploited?
There is no known exploitation of CVE-2026-68083 in the wild and no public exploit code.
Sources
Also known as AZL-95225, BELL-CVE-2026-68083, DEBIAN-CVE-2026-68083, GHSA-fxqh-hm36-rrq9, UBUNTU-CVE-2026-68083.