SB2026081587 - Improper access control in Linux kernel bpf

Description

This security bulletin contains information about 1 vulnerability.

1) Improper access control (CVE-ID: CVE-2026-74364)

CWE-ID: CWE-284 - Improper Access Control

CVSSv4: 7.1 [CVSS:4.0/AV:N/AC:L/AT:N/PR:L/UI:N/VC:N/VI:H/VA:N/SC:N/SI:N/SA:N]

The vulnerability allows a remote user to modify restricted map contents.

The vulnerability exists due to improper access control in bpf map-in-map handling when looking up and mutating an exclusive inner map through a non-exclusive outer map. A remote user can insert an exclusive map into a non-exclusive outer map and access it from an unrelated program to modify restricted map contents.

For the signed loader, this can defeat the metadata map exclusivity check by allowing cached map metadata to remain validated while the frozen map contents are rewritten through the outer map.

Remediation

Install update from vendor's website.

References

• https://git.kernel.org/stable/c/3a0f73d27a8d379a8852a378b3c3208143e3b3b2
• https://git.kernel.org/stable/c/7c58ace08f180f8e249e714d1623388362f9d807
• https://git.kernel.org/stable/c/9a3c3c49c333760c8944dadacbe114c1884546ef