CVE-2026-74283

Technical Description

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

tipc: require net admin for TIPCv2 netlink mutators

TIPCv2 registers mutating generic-netlink operations without admin

permission flags. Generic netlink only checks CAP_NET_ADMIN when an

operation sets GENL_ADMIN_PERM or GENL_UNS_ADMIN_PERM, so a local

unprivileged process can currently change TIPC state through commands

such as TIPC_NL_NET_SET, TIPC_NL_KEY_SET, TIPC_NL_KEY_FLUSH, and

bearer enable/disable.

The legacy TIPC netlink API already checks netlink_net_capable(...,

CAP_NET_ADMIN) for administrative commands. Give the TIPCv2 mutators

the equivalent generic-netlink gate. Use GENL_UNS_ADMIN_PERM, which

maps to the same namespace-aware CAP_NET_ADMIN check that

netlink_net_capable() performs, so the behaviour matches the legacy

path and keeps working for CAP_NET_ADMIN holders in a non-initial user

namespace (containers).

A QEMU/KASAN repro run as uid/gid 65534 with zero effective

capabilities previously succeed

Remediation

Check the references section for vendor advisories, patches, and mitigation guidance. If immediate patching is not possible, review the CVSS vector to understand the attack surface and apply compensating controls such as network segmentation or access restrictions.

References