Use-after-free in Linux kernel - CVE-2026-72381

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

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.

Linux kernel
Ubuntu
linux (Ubuntu package)
linux-realtime (Ubuntu package)
linux-oracle (Ubuntu package)
linux-gcp (Ubuntu package)
linux-aws (Ubuntu package)
linux-raspi (Ubuntu package)
linux-nvidia (Ubuntu package)
linux-ibm (Ubuntu package)
linux-nvidia-bos (Ubuntu package)
linux-hwe-7.0 (Ubuntu package)
linux-gcp-7.0 (Ubuntu package)
linux-oracle-7.0 (Ubuntu package)
linux-oem-7.0 (Ubuntu package)
linux-gke (Ubuntu package)
linux-aws-7.0 (Ubuntu package)
linux-nvidia-7.0 (Ubuntu package)
linux-azure-7.0 (Ubuntu package)
linux-azure (Ubuntu package)

Install security update from vendor's repository.

Linux kernel - update to 7.0 rc3
linux (Ubuntu package) - update to 7.0.0-34.34
linux-realtime (Ubuntu package) - update to 7.0.0-34.34.1
linux-oracle (Ubuntu package) - update to 7.0.0-1012.12
linux-gcp (Ubuntu package) - update to 7.0.0-1013.13
linux-aws (Ubuntu package) - update to 7.0.0-1013.13
linux-raspi (Ubuntu package) - update to 7.0.0-1020.20
linux-nvidia (Ubuntu package) - update to 7.0.0-1025.26
linux-ibm (Ubuntu package) - update to 7.0.0-1014.14
linux-nvidia-bos (Ubuntu package) - update to 7.0.0-2022.23
linux-hwe-7.0 (Ubuntu package) - update to 7.0.0-34.34~24.04.1
linux-gcp-7.0 (Ubuntu package) - update to 7.0.0-1013.13~24.04.1
linux-oracle-7.0 (Ubuntu package) - update to 7.0.0-1012.12~24.04.1
linux-oem-7.0 (Ubuntu package) - update to 7.0.0-1014.14
linux-gke (Ubuntu package) - update to 7.0.0-1007.8
linux-aws-7.0 (Ubuntu package) - update to 7.0.0-1013.13~24.04.1
linux-nvidia-7.0 (Ubuntu package) - update to 7.0.0-1024.25~24.04.1
linux-azure-7.0 (Ubuntu package) - addressed in versions 7.0.0-1016.16~24.04.1, 7.0.0-1017.17~24.04.1
linux-azure (Ubuntu package) - addressed in versions 7.0.0-1016.16, 7.0.0-1017.17

• 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

• Use-after-free in Linux kernel smb server
• Ubuntu update for linux-gcp
• Ubuntu update for linux
• Ubuntu update for linux-oracle-7.0
• Ubuntu update for linux-gke
• Ubuntu update for linux-azure-7.0
• Ubuntu update for linux-azure
• Ubuntu update for linux-nvidia-7.0, linux-nvidia-bos
• Ubuntu update for linux-nvidia