CVE-2026-23268

Summary

In the Linux kernel, the following vulnerability has been resolved:

apparmor: fix unprivileged local user can do privileged policy management

An unprivileged local user can load, replace, and remove profiles by opening the apparmorfs interfaces, via a confused deputy attack, by passing the opened fd to a privileged process, and getting the privileged process to write to the interface.

This does require a privileged target that can be manipulated to do the write for the unprivileged process, but once such access is achieved full policy management is possible and all the possible implications that implies: removing confinement, DoS of system or target applications by denying all execution, by-passing the unprivileged user namespace restriction, to exploiting kernel bugs for a local privilege escalation.

The policy management interface can not have its permissions simply changed from 0666 to 0600 because non-root processes need to be able to load policy to different policy namespaces.

Instead ensure the task writing the interface has privileges that are a subset of the task that opened the interface. This is already done via policy for confined processes, but unconfined can delegate access to the opened fd, by-passing the usual policy check.

Affected Software

VendorProductVersion RangeStatus
LinuxLinuxb7fd2c0340eacbee892425e9007647568b7f2a3c < a407a078cd41b5261b99d822af784bd9f136eb4daffected
LinuxLinuxb7fd2c0340eacbee892425e9007647568b7f2a3c < 4cafce4d6d0a66ec27e3af5637c11901d60189faaffected
LinuxLinuxb7fd2c0340eacbee892425e9007647568b7f2a3c < 33ee909702e047c94aaf41d4eea35626d509802caffected
LinuxLinuxb7fd2c0340eacbee892425e9007647568b7f2a3c < 17debf5586020790b5717f96e5e6a3ca5bb961abaffected
LinuxLinuxb7fd2c0340eacbee892425e9007647568b7f2a3c < 0fc63dd9170643d15c25681fca792539e23f4640affected
LinuxLinuxb7fd2c0340eacbee892425e9007647568b7f2a3c < b60b3f7a35c46b2e0ca934f9c988b8fca06d76c6affected
LinuxLinuxb7fd2c0340eacbee892425e9007647568b7f2a3c < b6a94eeca9c6c8f7c55ad44c62c98324f51ec596affected
LinuxLinuxb7fd2c0340eacbee892425e9007647568b7f2a3c < 6601e13e82841879406bf9f369032656f441a425affected
LinuxLinux4.11affected
LinuxLinux0 < 4.11unaffected
LinuxLinux5.10.253 <= 5.10.*unaffected
LinuxLinux5.15.203 <= 5.15.*unaffected
LinuxLinux6.1.169 <= 6.1.*unaffected
LinuxLinux6.6.130 <= 6.6.*unaffected
LinuxLinux6.12.77 <= 6.12.*unaffected
LinuxLinux6.18.18 <= 6.18.*unaffected
LinuxLinux6.19.8 <= 6.19.*unaffected
LinuxLinux7.0 <= *unaffected

Weaknesses

References