CVE-2026-63914

Technical Description

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

xfrm: route MIGRATE notifications to caller's netns

xfrm_send_migrate() in net/xfrm/xfrm_user.c and pfkey_send_migrate()

in net/key/af_key.c both hardcode &init_net for the multicast that

announces a successful XFRM_MSG_MIGRATE / SADB_X_MIGRATE.

XFRM_MSG_MIGRATE arrives on a per-netns NETLINK_XFRM socket, and the

rest of the xfrm/af_key netlink path was made netns-aware in 2008.

The other 14 multicast paths in xfrm_user.c route their event using

xs_net(x), xp_net(xp) or sock_net(skb->sk); only the migrate path

was missed.

Two consequences of the init_net hardcoding:

1. The notification (selector, old/new endpoint addresses, and the

km_address) is delivered to listeners on init_net's

XFRMNLGRP_MIGRATE / pfkey BROADCAST_ALL groups rather than on

the issuing netns. An IKE daemon running in init_net therefore

receives migration notifications originating from any other

netns on the host.

2

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