Improper input validation in Linux kernel - CVE-2026-90359

Vulnerability identifier: #VU151131

CSH Severity: Low

CVSS v4: 4.6 [CVSS:4.0/AV:L/AC:L/AT:N/PR:H/UI:N/VC:N/VI:L/VA:N/SC:N/SI:N/SA:N]

CVE-ID: CVE-2026-90359

CWE-ID: CWE-20

Exploitation vector: Local access

Exploit availability: No public exploit available

The vulnerability allows a local privileged user to corrupt function return values.

The vulnerability exists due to improper validation of return value size in BPF return-reading trampolines when attaching a BPF program to a function with a return value larger than 8 bytes. A local privileged user can attach a BPF program using a supported return-reading attach type to corrupt function return values.

Affected attach types include fexit, fmod_ret, fsession, their applicable multi variants, and struct_ops.

Linux kernel
Debian Linux
Ubuntu
linux (Ubuntu package)
linux-aws (Ubuntu package)
linux-gcp (Ubuntu package)
linux-oracle (Ubuntu package)
linux-ibm (Ubuntu package)
linux-hwe-7.0 (Ubuntu package)
linux-oem-7.0 (Ubuntu package)
linux (Debian package)

Install security update from vendor's repository.

linux (Ubuntu package) - update to 7.0.0-42.42
linux-aws (Ubuntu package) - update to 7.0.0-1016.17
linux-gcp (Ubuntu package) - update to 7.0.0-1016.18
linux-oracle (Ubuntu package) - update to 7.0.0-1015.16
linux-ibm (Ubuntu package) - update to 7.0.0-1017.17
linux-hwe-7.0 (Ubuntu package) - update to 7.0.0-42.42~24.04.1
linux-oem-7.0 (Ubuntu package) - update to 7.0.0-1017.17
linux (Debian package) - update to 6.12.115-2

• https://git.kernel.org/stable/c/c48796aa6c392cde93946e5d5a9a1f1b1cf72feb
• https://git.kernel.org/stable/c/d36ac53fc83baf843c51b7afd6d2471f36b713d8

• Improper input validation in Linux kernel bpf
• Debian update for linux
• Ubuntu update for linux-oem-7.0
• Ubuntu update for linux, linux-aws, linux-gcp and more