CyberSecBulletin
CVE-2026-63914NVD status: Analyzed

Linux: Exposure of Resource to Wrong Sphere

Published Updated By the CyberSecBulletin desk

CVE-2026-63914 is a high-severity exposure of resource to wrong sphere vulnerability in Linux, with a CVSS 3.1 base score of 7.3 out of 10. It can be exploited with local access to the system by an attacker with a low-privileged account, without any action from a user. The record lists versions bafc7d0774b9bf52909c70ed990bc5ccf7ec4bad, 6df8157547347b5257bf640a0ae3dfc4411e06cd, fe463798343382c8fe9416a95959f005a3c30aa5 as the first without the flaw, so updating Linux to one of those releases or later removes the exposure. There is no confirmed exploitation so far. EPSS estimates a 0.15% chance of exploitation within 30 days, which is low compared with other CVEs.

Next patch cycle

High severity with no evidence of exploitation so far.

What to do

  1. Update Linux to bafc7d0774b9bf52909c70ed990bc5ccf7ec4bad or 6df8157547347b5257bf640a0ae3dfc4411e06cd or fe463798343382c8fe9416a95959f005a3c30aa5 or 00f2c451e57df50b1151d9b2254878f106b7c892, whichever matches your release line, or a later version.
  2. Update Linux Kernel to 5.10.259 or 5.15.210 or 6.1.176 or 6.6.143, whichever matches your release line, or a later version.

Affected products and versions

VendorProductAffected versionsFixed in
LinuxLinux5c79de6e79cd8ecfbae28886be3ee49044f3a4d4 up to, but not including, bafc7d0774b9bf52909c70ed990bc5ccf7ec4bad; 5c79de6e79cd8ecfbae28886be3ee49044f3a4d4 up to, but not including, 6df8157547347b5257bf640a0ae3dfc4411e06cd; 5c79de6e79cd8ecfbae28886be3ee49044f3a4d4 up to, but not including, fe463798343382c8fe9416a95959f005a3c30aa5; 5c79de6e79cd8ecfbae28886be3ee49044f3a4d4 up to, but not including, 00f2c451e57df50b1151d9b2254878f106b7c892; 5c79de6e79cd8ecfbae28886be3ee49044f3a4d4 up to, but not including, a306cf2ac8849c487791369fad6f216399d000f6; 5c79de6e79cd8ecfbae28886be3ee49044f3a4d4 up to, but not including, 448bb92ca101dde8a6e88b4dc824044b4e341604; 5c79de6e79cd8ecfbae28886be3ee49044f3a4d4 up to, but not including, 26ce8dbf2e23fe4fcc3351d19ef6d3fb703ed126; 5c79de6e79cd8ecfbae28886be3ee49044f3a4d4 up to, but not including, 7e2a4f7ca0952820731ef7bdadfc9a9e9d3571b4; and 1 more rangesbafc7d0774b9bf52909c70ed990bc5ccf7ec4bad, 6df8157547347b5257bf640a0ae3dfc4411e06cd, fe463798343382c8fe9416a95959f005a3c30aa5, 00f2c451e57df50b1151d9b2254878f106b7c892, a306cf2ac8849c487791369fad6f216399d000f6, 448bb92ca101dde8a6e88b4dc824044b4e341604
LinuxLinux Kernel2.6.21 up to, but not including, 5.10.259; 5.11 up to, but not including, 5.15.210; 5.16 up to, but not including, 6.1.176; 6.2 up to, but not including, 6.6.143; 6.7 up to, but not including, 6.12.93; 6.13 up to, but not including, 6.18.35; 6.19 up to, but not including, 7.0.12; 7.15.10.259, 5.15.210, 6.1.176, 6.6.143, 6.12.93, 6.18.35

Version data comes from the organisation that assigned the CVE. Confirm against the vendor advisory before deciding you are unaffected.

How the severity score breaks down

Attack vector
LocalThe attacker needs local access or must trick a user into running something.
Attack complexity
LowNo special conditions are needed; the attack works reliably.
Privileges required
LowA basic user account is enough.
User interaction
NoneNo action by a victim is required.
Scope
ChangedThe attack can reach beyond the vulnerable component into other systems.
Confidentiality
HighAll data handled by the component can be read.
Integrity
NoneNothing can be modified.
Availability
LowPerformance or availability is reduced.

Vector: CVSS:3.1/AV:L/AC:L/PR:L/UI:N/S:C/C:H/I:N/A:L. Scored by CNA.

Official 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.

Source: the CVE record as published by its numbering authority, via NVD and CVE.org.

The underlying weakness: Exposure of Resource to Wrong Sphere

The product exposes a resource to the wrong control sphere, providing unintended actors with inappropriate access to the resource.

More Exposure of Resource to Wrong Sphere vulnerabilities (CWE-668)

Timeline

  1. CVE record published.
  2. CISA published its SSVC assessment (exploitation: none, automatable: no, technical impact: partial).
  3. Record last changed materially (score, affected products, status or references).

References

Recent Exposure of Resource to Wrong Sphere vulnerabilities

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