Exposed IOCTL with Insufficient Access Control in Linux kernel - CVE-2026-23256

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Main Vulnerability Database Vulnerabilities #VU124192

Exposed IOCTL with Insufficient Access Control in Linux kernel - CVE-2026-23256

Published: March 20, 2026


Vulnerability identifier: #VU124192
CSH Severity: Low
CVSS v4: 4.8 [CVSS:4.0/AV:L/AC:L/AT:N/PR:L/UI:N/VC:L/VI:N/VA:N/SC:N/SI:N/SA:N]
CVE-ID: CVE-2026-23256
CWE-ID: CWE-782
Exploitation vector: Local access
Exploit availability: No public exploit available

Vulnerability details

The vulnerability allows a local user to cause a memory leak.

The vulnerability exists due to an off-by-one error in the VF setup_nic_devices() cleanup function in the net: liquidio component when initializing network devices. A local user can trigger a failure during device setup to cause a memory leak.

The vulnerability specifically affects the cleanup logic in setup_nic_devices() where the loop fails to release memory for the current index on error path. This requires the ability to configure or trigger virtual function (VF) device initialization, typically available to privileged users.


Affected software

Linux kernel
Ubuntu
linux (Ubuntu package)
linux-xilinx-zynqmp (Ubuntu package)
linux-raspi (Ubuntu package)
linux-gcp-5.15 (Ubuntu package)
linux-oracle-5.15 (Ubuntu package)
linux-azure-fips (Ubuntu package)
linux-fips (Ubuntu package)
linux-nvidia-tegra (Ubuntu package)
linux-nvidia (Ubuntu package)
linux-nvidia-6.8 (Ubuntu package)
linux-azure (Ubuntu package)

How to mitigate CVE-2026-23256

Install security update from vendor's repository.

Linux kernel - update to 7.0 rc3
linux (Ubuntu package) - addressed in versions 5.15.0.183.154, 5.15.0-183.193, 5.15.0-183.193~20.04.1, 5.15.0.185.108, 5.15.0.185.166, 5.15.0-185.195+fips1, 5.15.0-185.195~20.04.1, 5.15.0-1052.52, 5.15.0.1052.54, 5.15.0-1063.63, 5.15.0-1063.63~20.04.1, 5.15.0.1094.93, 5.15.0-1094.102, 5.15.0.1103.99, 5.15.0-1103.105, 5.15.0.1103.107, 5.15.0-1103.108, 5.15.0.1105.102, 5.15.0.1105.109, 5.15.0-1105.109~20.04.1, 5.15.0.1106.105, 5.15.0.1106.106, 5.15.0-1106.107, 5.15.0-1106.112, 5.15.0.1107.106, 5.15.0-1107.113, 5.15.0.1108.104, 5.15.0-1108.114, 5.15.0.1110.114, 5.15.0-1110.119, 5.15.0.1111.101, 5.15.0.1111.107, 5.15.0.1111.108, 5.15.0.1111.114, 5.15.0-1111.118, 5.15.0-1111.118+fips1, 5.15.0-1111.118~20.04.1, 5.15.0-1111.121, 5.15.0-1111.121+fips1, 5.15.0.1116.114, 5.15.0-1116.125, 5.15.0-1116.125~20.04.1, 6.8.0-117.117, 6.8.0-117.117.1, 6.8.0-117.117.1~22.04.1, 6.8.0-1041.44, 6.8.0-1054.60, 6.8.0-1055.56, 6.8.0-1055.56~22.04.1, 6.8.0-1055.58+fips1, 6.8.0-1056.60, 6.8.0-1058.61, 6.8.0-1058.61+fips1, 6.8.0-2045.46, 6.8.1-1051.52, 6.8.1-1051.52~22.04.1
linux-xilinx-zynqmp (Ubuntu package) - addressed in versions 5.15.0.1074.77, 5.15.0-1074.78
linux-raspi (Ubuntu package) - addressed in versions 5.15.0.1105.103, 5.15.0-1105.108
linux-gcp-5.15 (Ubuntu package) - addressed in versions 5.15.0-1106.112~20.04.1, 5.15.0-1111.121~20.04.1
linux-oracle-5.15 (Ubuntu package) - update to 5.15.0-1108.114~20.04.1
linux-azure-fips (Ubuntu package) - addressed in versions 5.15.0.1116.101, 5.15.0-1116.125+fips1
linux-fips (Ubuntu package) - update to 6.8.0-116.116+fips1
linux-nvidia-tegra (Ubuntu package) - update to 6.8.0-1024.24
linux-nvidia (Ubuntu package) - addressed in versions 6.8.0-1054.57, 6.8.0-1054.57.1
linux-nvidia-6.8 (Ubuntu package) - update to 6.8.0-1054.57~22.04.1
linux-azure (Ubuntu package) - update to 6.8.0-1056.62

External References

Related Security Bulletins