Use-after-free in Linux kernel - CVE-2026-43378
Published: May 9, 2026
Vulnerability identifier: #VU130813
CSH Severity: Low
CVSS v4: 8.5 [CVSS:4.0/AV:L/AC:L/AT:N/PR:L/UI:N/VC:H/VI:H/VA:H/SC:N/SI:N/SA:N]
CVE-ID: CVE-2026-43378
CWE-ID: CWE-416
Exploitation vector: Local access
Exploit availability:
No public exploit available
Vulnerability details
The vulnerability allows a local user to execute arbitrary code.
The vulnerability exists due to use-after-free in smb2_open() when handling SMB open requests. A local user can trigger a race condition involving a dangling opinfo pointer to execute arbitrary code.
Affected software
Linux kernel
Ubuntu
linux (Ubuntu package)
linux-azure-fips (Ubuntu package)
linux-hwe-6.8 (Ubuntu package)
linux-nvidia-tegra (Ubuntu package)
linux-aws-6.8 (Ubuntu package)
linux-raspi (Ubuntu package)
linux-azure-fde (Ubuntu package)
linux-azure-fde-6.8 (Ubuntu package)
linux-azure (Ubuntu package)
linux-raspi-realtime (Ubuntu package)
linux-hwe-6.17 (Ubuntu package)
linux-azure-fde-6.17 (Ubuntu package)
linux-azure-6.17 (Ubuntu package)
linux-nvidia-6.17 (Ubuntu package)
linux-oem-6.17 (Ubuntu package)
Ubuntu
linux (Ubuntu package)
linux-azure-fips (Ubuntu package)
linux-hwe-6.8 (Ubuntu package)
linux-nvidia-tegra (Ubuntu package)
linux-aws-6.8 (Ubuntu package)
linux-raspi (Ubuntu package)
linux-azure-fde (Ubuntu package)
linux-azure-fde-6.8 (Ubuntu package)
linux-azure (Ubuntu package)
linux-raspi-realtime (Ubuntu package)
linux-hwe-6.17 (Ubuntu package)
linux-azure-fde-6.17 (Ubuntu package)
linux-azure-6.17 (Ubuntu package)
linux-nvidia-6.17 (Ubuntu package)
linux-oem-6.17 (Ubuntu package)
How to mitigate CVE-2026-43378
Install security update from vendor's repository.
Linux kernel - update to 7.0 rc3
linux (Ubuntu package) - addressed in versions 6.8.0-134.134, 6.8.0-1057.58~22.04.1, 6.8.0-1058.61+fips1, 6.8.0-1058.61~22.04.1, 6.8.0-1060.61, 6.8.0-1060.63+fips1, 6.8.0-1060.63~22.04.1, 6.8.0-1063.69, 6.8.0-1063.69+fips1, 6.8.1-1055.56, 6.8.1-1055.56~22.04.1, 6.17.0-40.40
linux-azure-fips (Ubuntu package) - addressed in versions 6.8.0-134.134+fips1, 6.8.0-1062.69+fips1
linux-hwe-6.8 (Ubuntu package) - update to 6.8.0-136.136~22.04.1
linux-nvidia-tegra (Ubuntu package) - update to 6.8.0-1029.30
linux-aws-6.8 (Ubuntu package) - addressed in versions 6.8.0-1045.48, 6.8.0-1057.58~22.04.1, 6.8.0-1058.61.1, 6.8.0-1058.64, 6.8.0-1060.61~22.04.1, 6.8.0-1060.63~22.04.1, 6.8.0-1063.69~22.04.1
linux-raspi (Ubuntu package) - addressed in versions 6.8.0-1060.64, 6.17.0-1021.21
linux-azure-fde (Ubuntu package) - update to 6.8.0-1062.69
linux-azure-fde-6.8 (Ubuntu package) - update to 6.8.0-1062.69~22.04.1
linux-azure (Ubuntu package) - addressed in versions 6.8.0-1063.71, 6.8.0-1063.71~22.04.1
linux-raspi-realtime (Ubuntu package) - update to 6.8.0-2049.50
linux-hwe-6.17 (Ubuntu package) - update to 6.17.0-40.40~24.04.1
linux-azure-fde-6.17 (Ubuntu package) - update to 6.17.0-1018.18~24.04.1
linux-azure-6.17 (Ubuntu package) - update to 6.17.0-1021.21~24.04.1
linux-nvidia-6.17 (Ubuntu package) - update to 6.17.0-1026.26
linux-oem-6.17 (Ubuntu package) - update to 6.17.0-1028.28
linux (Ubuntu package) - addressed in versions 6.8.0-134.134, 6.8.0-1057.58~22.04.1, 6.8.0-1058.61+fips1, 6.8.0-1058.61~22.04.1, 6.8.0-1060.61, 6.8.0-1060.63+fips1, 6.8.0-1060.63~22.04.1, 6.8.0-1063.69, 6.8.0-1063.69+fips1, 6.8.1-1055.56, 6.8.1-1055.56~22.04.1, 6.17.0-40.40
linux-azure-fips (Ubuntu package) - addressed in versions 6.8.0-134.134+fips1, 6.8.0-1062.69+fips1
linux-hwe-6.8 (Ubuntu package) - update to 6.8.0-136.136~22.04.1
linux-nvidia-tegra (Ubuntu package) - update to 6.8.0-1029.30
linux-aws-6.8 (Ubuntu package) - addressed in versions 6.8.0-1045.48, 6.8.0-1057.58~22.04.1, 6.8.0-1058.61.1, 6.8.0-1058.64, 6.8.0-1060.61~22.04.1, 6.8.0-1060.63~22.04.1, 6.8.0-1063.69~22.04.1
linux-raspi (Ubuntu package) - addressed in versions 6.8.0-1060.64, 6.17.0-1021.21
linux-azure-fde (Ubuntu package) - update to 6.8.0-1062.69
linux-azure-fde-6.8 (Ubuntu package) - update to 6.8.0-1062.69~22.04.1
linux-azure (Ubuntu package) - addressed in versions 6.8.0-1063.71, 6.8.0-1063.71~22.04.1
linux-raspi-realtime (Ubuntu package) - update to 6.8.0-2049.50
linux-hwe-6.17 (Ubuntu package) - update to 6.17.0-40.40~24.04.1
linux-azure-fde-6.17 (Ubuntu package) - update to 6.17.0-1018.18~24.04.1
linux-azure-6.17 (Ubuntu package) - update to 6.17.0-1021.21~24.04.1
linux-nvidia-6.17 (Ubuntu package) - update to 6.17.0-1026.26
linux-oem-6.17 (Ubuntu package) - update to 6.17.0-1028.28
External References
- https://git.kernel.org/stable/c/190e5f808e8058640b408ccfed25440b441a718a
- https://git.kernel.org/stable/c/1e689a56173827669a35da7cb2a3c78ed5c53680
- https://git.kernel.org/stable/c/54b48ae83de8bb06e65079d96368efe359d4909c
- https://git.kernel.org/stable/c/8f5b1a7cb009a93c48e9e334a2f59a660f9afc07
- https://git.kernel.org/stable/c/b720c84087cb547f23ce03eab93568c1769e4556
- https://git.kernel.org/stable/c/e1b21e6066615e7d3d3a7aa2677e415e563fd7cc
Related Security Bulletins
- Use-after-free in Linux kernel smb server
- Ubuntu update for linux-oem-6.17
- Ubuntu update for linux
- Ubuntu update for linux
- Ubuntu update for linux-nvidia-tegra
- Ubuntu update for linux-aws-6.8
- Ubuntu update for linux-nvidia-6.17
- Ubuntu update for linux-raspi-realtime
- Ubuntu update for linux-raspi
- Ubuntu update for linux-raspi
- Ubuntu update for linux-azure-fips
- Ubuntu update for linux-hwe-6.17
- Ubuntu update for linux-raspi
- Ubuntu update for linux-azure-fde-6.8
- Ubuntu update for linux-azure-fde
- Ubuntu update for linux-azure
- Ubuntu update for linux-azure-fde-6.17
- Ubuntu update for linux-azure-6.17
- Ubuntu update for linux-hwe-6.8