Out-of-bounds write in Linux kernel - CVE-2026-90327
Published: September 18, 2026
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
Vulnerability details
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.
Affected software
Linux kernel
How to mitigate CVE-2026-90327
Install security update from vendor's repository.
External References
- 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