CVE-2026-68083: ksmbd: fix path resolution in ksmbd_vfs_kern_path_create
In the Linux kernel, the following vulnerability has been resolved:
ksmbd: fix path resolution in ksmbdvfskernpathcreate
The SMB2 open lookup is rooted at the share with LOOKUPBENEATH, but the create/mkdir/hardlink sink is not: ksmbdvfskernpathcreate() builds an absolute path with converttounixname() and resolves it from ATFDCWD via startcreatingpath(), 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 vfspathparentlookup(..., LOOKUPBENEATH, &shareconf->vfspath) and create the final component with startcreatingnoperm(). converttounixname() then has no callers and is removed.
Affected Software
Event History
Frequently Asked Questions
What is the severity of CVE-2026-68083?
The severity of CVE-2026-68083 is rated as 55, indicating a moderate risk.
How do I fix CVE-2026-68083?
To fix CVE-2026-68083, you should update your Linux Kernel to the latest version where this vulnerability has been addressed.
What systems are affected by CVE-2026-68083?
CVE-2026-68083 affects the Linux Kernel, particularly the implementations using ksmbd.
What is the impact of CVE-2026-68083?
The impact of CVE-2026-68083 includes potential path resolution failures leading to improper handling of file operations.
Is there a known exploit for CVE-2026-68083?
As of now, there are no public reports of active exploits targeting CVE-2026-68083.