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CVE-2026-63914

HIGH 7.3

Published 2026-07-19 · Last modified 2026-07-20

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.

ELEVATED IMPACT

Severe if exploited (CVSS 7.3), but no known exploitation and low modeled probability. Patch on a normal cadence.

Exploitation likelihood

0.2%chance of exploitation in 30 days · 5th percentile

○ In CISA KEV ○ Public exploit / PoC

Impact if exploited

7.3CVSS 3.1 · HIGH

  • ConfidentialityHigh
  • IntegrityNone
  • AvailabilityLow

What an attacker needs

  • Access: Requires local access to the host
  • Privileges: Requires a low-privilege account
  • User interaction: No user interaction needed
  • Complexity: No special conditions — reliably repeatable

✓ lowers the bar for an attacker · ⚠ raises it

Proof of concept & exploit code

Test against your own equipment

curl -s https://vulnpedia.com/cve/CVE-2026-63914/poc.jsonMachine-readable PoC index for this CVE (for automation).

Listed for defensive triage, patch verification, and authorized testing on systems you own. Machine-readable: /cve/CVE-2026-63914/poc.json

Affected

Vendors Linux

Products Linux

Weakness (CWE)

Not classified.

CVSS vector

CVSS:3.1/AV:L/AC:L/PR:L/UI:N/S:C/C:H/I:N/A:L

All CVSS metrics

  • HIGH 7.3 v3.1 · CNA Primary
    CVSS:3.1/AV:L/AC:L/PR:L/UI:N/S:C/C:H/I:N/A:L
  • HIGH 7.3 v3.1 · NVD Secondary
    CVSS:3.1/AV:L/AC:L/PR:L/UI:N/S:C/C:H/I:N/A:L

Sources: NVD · CVE.org · EPSS