Use-after-free in Linux kernel - CVE-2026-64142
Published: July 20, 2026
Vulnerability identifier: #VU138479
CSH Severity: Medium
CVSS v4.0: CVSS:4.0/AV:N/AC:L/AT:P/PR:L/UI:N/VC:N/VI:N/VA:H/SC:N/SI:N/SA:N/E:U/U:Green
CVE-ID: CVE-2026-64142
CWE-ID: CWE-416
Exploitation vector: Remote access
Exploit availability:
No public exploit available
Vendor: Linux Foundation
Affected software:
Linux kernel
Linux kernel
Detailed vulnerability description
The vulnerability allows a remote user to cause a denial of service and potentially execute arbitrary code.
The vulnerability exists due to use-after-free in ksmbd durable handle management and m_fp_list walkers when processing concurrent durable-handle expiration and file lookup operations. A remote user can trigger concurrent durable handle expiration and lookup activity to cause a denial of service and potentially execute arbitrary code.
The issue involves a race between the durable scavenger and walkers such as ksmbd_lookup_fd_inode() and share-mode checks, and exploitation requires access to SMB operations that exercise durable handles.
How to mitigate CVE-2026-64142
Install security update from vendor's repository.
Sources
- https://git.kernel.org/stable/c/1f8f3246d55f89350a1a67bdf3744b7241048e4e
- https://git.kernel.org/stable/c/3a436932eb397e909d0607d76a8325abd9d85a35
- https://git.kernel.org/stable/c/5da69a65b282d2276de22e5194ba0f88c836170c
- https://git.kernel.org/stable/c/95f072ef934ca00711d510676b8792cbf59a5aae
- https://git.kernel.org/stable/c/bf736184d063da1a552ffeff0481813599a182cc