Out-of-bounds write in Linux kernel - CVE-2026-90327

Vulnerability identifier: #VU151162

CSH Severity: Low

CVSS v4: 4.8 [CVSS:4.0/AV:L/AC:L/AT:N/PR:L/UI:N/VC:N/VI:L/VA:N/SC:N/SI:N/SA:N]

CVE-ID: CVE-2026-90327

CWE-ID: CWE-787

Exploitation vector: Local access

Exploit availability: No public exploit available

The vulnerability allows a local user to write up to three bytes beyond a user-supplied buffer.

The vulnerability exists due to an out-of-bounds write in the phonet PEP socket option handler pep_getsockopt() when calling getsockopt() with an optlen smaller than sizeof(int). A local user can invoke getsockopt() with a small optlen to write up to three bytes beyond a user-supplied buffer.

Linux kernel
Debian Linux
Ubuntu
linux-nvidia-tegra-igx (Ubuntu package)
linux-nvidia-tegra (Ubuntu package)
linux-nvidia-tegra-5.15 (Ubuntu package)
linux-azure-fde (Ubuntu package)
linux (Ubuntu package)
linux-oracle (Ubuntu package)
linux-gcp (Ubuntu package)
linux-aws (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-nvidia-tegra-igx (Ubuntu package) - update to 5.15.0-1059.59
linux-nvidia-tegra (Ubuntu package) - update to 5.15.0-1070.72
linux-nvidia-tegra-5.15 (Ubuntu package) - update to 5.15.0-1070.72~20.04.1
linux-azure-fde (Ubuntu package) - update to 5.15.0-1124.133
linux (Ubuntu package) - update to 7.0.0-42.42
linux-oracle (Ubuntu package) - update to 7.0.0-1015.16
linux-gcp (Ubuntu package) - update to 7.0.0-1016.18
linux-aws (Ubuntu package) - update to 7.0.0-1016.17
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 6.12.111-1

• https://git.kernel.org/stable/c/056eea1a2068ad2fb7c3093c5f1095268f87d0c7
• https://git.kernel.org/stable/c/1bf499e438da80455e258049bce60ffb3a53f3fa
• https://git.kernel.org/stable/c/6054fed6bad08b6d03973e8ffca7f0c9394d1c30
• https://git.kernel.org/stable/c/77e5eb0e192aec6710c03ca8144582fd2af36ca4
• https://git.kernel.org/stable/c/95e0ed2439dd1792eb454c68ae8d10f30ffe3bff
• https://git.kernel.org/stable/c/c4487e4d5309de587479ecc2f5173b49586f46f4
• https://git.kernel.org/stable/c/eac733a0b6fe0a52d91f9f623425735ed50ac6c2
• https://git.kernel.org/stable/c/f97022fefe6eb06ee18549d603420440f2959802

• Out-of-bounds write in Linux kernel phonet
• Debian update for linux
• Ubuntu update for linux-azure-fde
• Ubuntu update for linux-oem-7.0
• Ubuntu update for linux, linux-aws, linux-gcp and more
• Ubuntu update for linux-nvidia-tegra, linux-nvidia-tegra-5.15, linux-nvidia-tegra-igx
• Ubuntu update for linux, linux-aws, linux-aws-5.15 and more