SB20260529194 - Improper access control in Linux kernel selinux

Description

This security bulletin contains information about 1 vulnerability.

1) Improper access control (CVE-ID: CVE-2026-46104)

CWE-ID: CWE-284 - Improper Access Control

CVSSv4: CVSS:4.0/AV:L/AC:L/AT:N/PR:L/UI:N/VC:L/VI:L/VA:N/SC:N/SI:N/SA:N/E:U/U:Clear

The vulnerability allows a local user to bypass SELinux socket permission checks.

The vulnerability exists due to improper access control in sock_has_perm() and nlmsg_sock_has_extended_perms() when handling socket permission checks in stacked LSM configurations. A local user can trigger access checks on a socket with an incorrectly interpreted security blob to bypass SELinux socket permission checks.

The issue occurs when another LSM allocates socket blob storage before SELinux, causing invalid SID and class values to be used in AVC checks.

Remediation

Install update from vendor's website.

References

• https://git.kernel.org/stable/c/032e70aff025d7c519af9ab791cd084380619263
• https://git.kernel.org/stable/c/7eca71f57f194c1638ebb7f4097d6be8fd04c101
• https://git.kernel.org/stable/c/d350fef4bc2467fe1bce15f7a20fe60e01ce41ad