Use-after-free in Linux kernel - CVE-2026-72381
Published: August 15, 2026
Vulnerability identifier: #VU143062
CSH Severity: Medium
CVSS v4: 7.1 [CVSS:4.0/AV:N/AC:L/AT:N/PR:L/UI:N/VC:N/VI:N/VA:H/SC:N/SI:N/SA:N]
CVE-ID: CVE-2026-72381
CWE-ID: CWE-416
Exploitation vector: Remote access
Exploit availability:
No public exploit available
Vulnerability details
The vulnerability allows a remote user to cause a denial of service.
The vulnerability exists due to a use-after-free in ksmbd_vfs_compare_durable_owner() when processing concurrent SMB2 durable reconnect requests on the same persistent_id. A remote user can trigger concurrent durable reconnect operations to cause a denial of service.
The issue occurs because a comparison of owner.name can race with memory being freed in the durable file reopen path.
Affected software
Linux kernel
Ubuntu
linux (Ubuntu package)
linux-gcp (Ubuntu package)
Ubuntu
linux (Ubuntu package)
linux-gcp (Ubuntu package)
How to mitigate CVE-2026-72381
Install security update from vendor's repository.
Linux kernel - update to 7.0 rc3
linux (Ubuntu package) - addressed in versions 7.0.0-34.34, 7.0.0-34.34.1, 7.0.0-34.34~24.04.1, 7.0.0-1012.12~24.04.1, 7.0.0-1013.13, 7.0.0-1013.13~24.04.1, 7.0.0-1014.14, 7.0.0-1020.20
linux-gcp (Ubuntu package) - addressed in versions 7.0.0-1013.13, 7.0.0-1013.13~24.04.1, 7.0.0-1014.14
linux (Ubuntu package) - addressed in versions 7.0.0-34.34, 7.0.0-34.34.1, 7.0.0-34.34~24.04.1, 7.0.0-1012.12~24.04.1, 7.0.0-1013.13, 7.0.0-1013.13~24.04.1, 7.0.0-1014.14, 7.0.0-1020.20
linux-gcp (Ubuntu package) - addressed in versions 7.0.0-1013.13, 7.0.0-1013.13~24.04.1, 7.0.0-1014.14
External References
- https://git.kernel.org/stable/c/38637163501fd9e2f684b8cd275d0db5d79f37c6
- https://git.kernel.org/stable/c/5a5ac2852cd326529d02f778bc1aa6184701f4d7
- https://git.kernel.org/stable/c/93d4d46bf9d442a12ea87278049ec416962c627f
- https://git.kernel.org/stable/c/ed98719be41389d416953b8ef9f07a07dfea6b2b
- https://git.kernel.org/stable/c/fb978d72052704c6b06c6b0f129fcd60b77169f5