Use-after-free in Linux kernel - CVE-2026-43378

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Main Vulnerability Database Vulnerabilities #VU130813

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-fips (Ubuntu package)
linux-lowlatency (Ubuntu package)
linux-azure-5.15 (Ubuntu package)
linux-nvidia-tegra-igx (Ubuntu package)
linux-raspi (Ubuntu package)
linux-oracle (Ubuntu package)
linux-aws-5.15 (Ubuntu package)
linux-azure-fde-5.15 (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-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 5.15.0.187.167, 5.15.0-187.197, 5.15.0.1065.65, 5.15.0-1065.67, 5.15.0-1065.67~20.04.1, 5.15.0.1076.79~20.04.1, 5.15.0-1076.80, 5.15.0.1096.95, 5.15.0-1096.104, 5.15.0.1105.101, 5.15.0-1105.107, 5.15.0.1105.109, 5.15.0-1105.110, 5.15.0.1107.104, 5.15.0.1107.111, 5.15.0-1107.111~20.04.1, 5.15.0.1108.107, 5.15.0.1108.108, 5.15.0-1108.109, 5.15.0-1108.114, 5.15.0-1108.114~20.04.1, 5.15.0-1110.116~20.04.1, 5.15.0.1112.116, 5.15.0-1112.121, 5.15.0.1113.109, 5.15.0.1113.116, 5.15.0-1113.120, 5.15.0-1113.120+fips1, 5.15.0.1118.103, 5.15.0.1118.116, 5.15.0-1118.127, 5.15.0-1118.127+fips1, 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-fips (Ubuntu package) - addressed in versions 5.15.0.190.111, 5.15.0-190.200+fips1, 5.15.0.1110.109, 5.15.0-1110.116
linux-lowlatency (Ubuntu package) - addressed in versions 5.15.0.190.157, 5.15.0-190.200
linux-azure-5.15 (Ubuntu package) - addressed in versions 5.15.0-190.200~20.04.1, 5.15.0.1114.104, 5.15.0.1114.111, 5.15.0-1114.124, 5.15.0-1114.124+fips1, 5.15.0-1119.128~20.04.1
linux-nvidia-tegra-igx (Ubuntu package) - addressed in versions 5.15.0-1054.54, 5.15.0.1054.56
linux-raspi (Ubuntu package) - addressed in versions 5.15.0.1108.106, 5.15.0-1108.111, 6.8.0-1060.64, 6.17.0-1021.21
linux-oracle (Ubuntu package) - addressed in versions 5.15.0.1110.106, 5.15.0-1110.116
linux-aws-5.15 (Ubuntu package) - addressed in versions 5.15.0-1114.121~20.04.1, 5.15.0-1114.124~20.04.1
linux-azure-fde-5.15 (Ubuntu package) - update to 5.15.0-1118.127~20.04.1
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-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

Related Security Bulletins