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Full vulnerability report · 2026
CVE-2026-43167High confidence

xfrm: always flush state and policy upon NETDEV_UNREGISTER event

Linux · Linux

5.5MediumCVSS 3.1
Recommended action
Patch only the product branches with a verified fix

Medium technical severity with no CISA KEV confirmation; remediate through the normal risk-based patch cycle unless local exposure raises the priority. Verified remediation exists for at least one product or source, but 21 structured product or package states remain unresolved. Apply remediation only to the exact product branch confirmed by its source.

Fix availability varies by product
R
Operational reassessment

Published severity in operational context

Open reassessment dashboard →
Published severityMediumOperational priority:Low, lowered one band.downgradedsince 11 May 2026

Evidence used

  • No CISA KEV confirmation is currently recorded.
  • Exploitation requires an existing local or physical foothold with privileges.
  • EPSS is 0.16% for the current model date.

Compensating controls

  • Validate the affected product branch and deploy the verified fixed release.
  • Restrict local access and enforce least privilege on affected hosts.
  • Monitor vendor guidance and exploitation sources for a material change.

Verification

  1. Confirm that the asset runs Linux Linux and falls inside the recorded affected range.
  2. Verify the installed build against the product-specific fixed version after deployment.
  3. Validate exposure, authentication requirements and compensating controls in the actual environment.
  4. Reopen this reassessment when CVSS, KEV, EPSS, exploit evidence or remediation changes.
Mitigation target: No default targetRemediation target: Normal maintenance

This automated reassessment organises public evidence. It does not know asset exposure, business impact or control effectiveness and does not replace CVSS or a human risk decision.

Cross-source reconciliation

Remediation availability differs by product scope

Verified remediation exists for at least one product or source, but 21 structured product or package states remain unresolved. Apply remediation only to the exact product branch confirmed by its source.

Distribution package intelligence

Release-specific package status

Debian, ubuntu findings are scoped to the named distribution, release and source package. An absent finding does not mean a package is unaffected.

24 package states
Package result overrides the generic status

BlackTree has verified remediation for at least one product or source, but the relevant distribution still reports no fixed package for 21 affected package states shown here. Treat those rows as affected with no fix until that distribution publishes a fixed version.

Repository candidate not checked

A published vendor fix does not prove that a matching update is enabled and installable on a particular asset. Confirm the local package candidate before scheduling remediation.

Distribution releaseSource packageVendor stateFixed versionEvidence
Debian trixietrixie · sourcelinuxVendor fix publishedDebian records a fixed source-package version for this release.6.12.85-1Debian Security Tracker ↗Source updated 5 Oct 2026
Debian bookwormbookworm · sourcelinuxAffected, no fix publishedDebian currently tracks this release as open.Not published in this feedDebian Security Tracker ↗Source updated 5 Oct 2026
Debian forkyforky · sourcelinuxVendor fix publishedDebian records a fixed source-package version for this release.6.19.6-1Debian Security Tracker ↗Source updated 5 Oct 2026
Debian sidsid · sourcelinuxVendor fix publishedDebian records a fixed source-package version for this release.6.19.6-1Debian Security Tracker ↗Source updated 5 Oct 2026
Ubuntu 24.04 LTSnoble · standard archivelinuxAffected, no fix publishedCanonical OVAL identifies this running kernel flavour as affected and does not publish a fixed package version in this definition.Not published in this feedCanonical Ubuntu Security ↗Source updated 5 Oct 2026
Ubuntu 24.04 LTSnoble · standard archivelinux-awsAffected, no fix publishedCanonical OVAL identifies this running kernel flavour as affected and does not publish a fixed package version in this definition.Not published in this feedCanonical Ubuntu Security ↗Source updated 5 Oct 2026
Ubuntu 24.04 LTSnoble · standard archivelinux-azureAffected, no fix publishedCanonical OVAL identifies this running kernel flavour as affected and does not publish a fixed package version in this definition.Not published in this feedCanonical Ubuntu Security ↗Source updated 5 Oct 2026
Ubuntu 24.04 LTSnoble · standard archivelinux-azure-fdeAffected, no fix publishedCanonical OVAL identifies this running kernel flavour as affected and does not publish a fixed package version in this definition.Not published in this feedCanonical Ubuntu Security ↗Source updated 5 Oct 2026
Ubuntu 24.04 LTSnoble · standard archivelinux-azure-nvidiaAffected, no fix publishedCanonical OVAL identifies this running kernel flavour as affected and does not publish a fixed package version in this definition.Not published in this feedCanonical Ubuntu Security ↗Source updated 5 Oct 2026
Ubuntu 24.04 LTSnoble · standard archivelinux-gcpAffected, no fix publishedCanonical OVAL identifies this running kernel flavour as affected and does not publish a fixed package version in this definition.Not published in this feedCanonical Ubuntu Security ↗Source updated 5 Oct 2026
Ubuntu 24.04 LTSnoble · standard archivelinux-gkeAffected, no fix publishedCanonical OVAL identifies this running kernel flavour as affected and does not publish a fixed package version in this definition.Not published in this feedCanonical Ubuntu Security ↗Source updated 5 Oct 2026
Ubuntu 24.04 LTSnoble · standard archivelinux-gkeopAffected, no fix publishedCanonical OVAL identifies this running kernel flavour as affected and does not publish a fixed package version in this definition.Not published in this feedCanonical Ubuntu Security ↗Source updated 5 Oct 2026
Ubuntu 24.04 LTSnoble · standard archivelinux-ibmAffected, no fix publishedCanonical OVAL identifies this running kernel flavour as affected and does not publish a fixed package version in this definition.Not published in this feedCanonical Ubuntu Security ↗Source updated 5 Oct 2026
Ubuntu 24.04 LTSnoble · standard archivelinux-lowlatencyAffected, no fix publishedCanonical OVAL identifies this running kernel flavour as affected and does not publish a fixed package version in this definition.Not published in this feedCanonical Ubuntu Security ↗Source updated 5 Oct 2026
Ubuntu 24.04 LTSnoble · standard archivelinux-nvidiaAffected, no fix publishedCanonical OVAL identifies this running kernel flavour as affected and does not publish a fixed package version in this definition.Not published in this feedCanonical Ubuntu Security ↗Source updated 5 Oct 2026
Ubuntu 24.04 LTSnoble · standard archivelinux-nvidia-lowlatencyAffected, no fix publishedCanonical OVAL identifies this running kernel flavour as affected and does not publish a fixed package version in this definition.Not published in this feedCanonical Ubuntu Security ↗Source updated 5 Oct 2026
Ubuntu 24.04 LTSnoble · standard archivelinux-nvidia-tegraAffected, no fix publishedCanonical OVAL identifies this running kernel flavour as affected and does not publish a fixed package version in this definition.Not published in this feedCanonical Ubuntu Security ↗Source updated 5 Oct 2026
Ubuntu 24.04 LTSnoble · standard archivelinux-oem-6.11Affected, no fix publishedCanonical OVAL identifies this running kernel flavour as affected and does not publish a fixed package version in this definition.Not published in this feedCanonical Ubuntu Security ↗Source updated 5 Oct 2026
Ubuntu 24.04 LTSnoble · standard archivelinux-oracleAffected, no fix publishedCanonical OVAL identifies this running kernel flavour as affected and does not publish a fixed package version in this definition.Not published in this feedCanonical Ubuntu Security ↗Source updated 5 Oct 2026
Ubuntu 24.04 LTSnoble · standard archivelinux-raspiAffected, no fix publishedCanonical OVAL identifies this running kernel flavour as affected and does not publish a fixed package version in this definition.Not published in this feedCanonical Ubuntu Security ↗Source updated 5 Oct 2026
Ubuntu 24.04 LTSnoble · standard archivelinux-raspi-realtimeAffected, no fix publishedCanonical OVAL identifies this running kernel flavour as affected and does not publish a fixed package version in this definition.Not published in this feedCanonical Ubuntu Security ↗Source updated 5 Oct 2026
Ubuntu 24.04 LTSnoble · standard archivelinux-realtimeAffected, no fix publishedCanonical OVAL identifies this running kernel flavour as affected and does not publish a fixed package version in this definition.Not published in this feedCanonical Ubuntu Security ↗Source updated 5 Oct 2026
Ubuntu 24.04 LTSnoble · standard archivelinux-riscvAffected, no fix publishedCanonical OVAL identifies this running kernel flavour as affected and does not publish a fixed package version in this definition.Not published in this feedCanonical Ubuntu Security ↗Source updated 5 Oct 2026
Ubuntu 24.04 LTSnoble · standard archivelinux-xilinxAffected, no fix publishedCanonical OVAL identifies this running kernel flavour as affected and does not publish a fixed package version in this definition.Not published in this feedCanonical Ubuntu Security ↗Source updated 5 Oct 2026
Direct vendor intelligence

Authoritative vendor CSAF and VEX advisories

Structured product status and remediation from the issuing vendor. Product-state explanations are always visible; large lists can be searched or downloaded.

1 current
CVE-2026-43167 · CSAF 2.0 · revision 14 · interimSUSE Product Security TeamCVE-2026-43167
320 known affected

The vendor explicitly identifies these products as affected by this CVE.

  • kernel-default as component of SUSE Linux Enterprise High Performance Computing 12 SP4
  • kernel-default-base as component of SUSE Linux Enterprise High Performance Computing 12 SP4
  • kernel-default-devel as component of SUSE Linux Enterprise High Performance Computing 12 SP4
  • kernel-default-man as component of SUSE Linux Enterprise High Performance Computing 12 SP4
  • kernel-devel as component of SUSE Linux Enterprise High Performance Computing 12 SP4
  • kernel-macros as component of SUSE Linux Enterprise High Performance Computing 12 SP4
  • kernel-source as component of SUSE Linux Enterprise High Performance Computing 12 SP4
  • cluster-md-kmp-default as component of SUSE Linux Enterprise High Performance Computing 12 SP5
  • dlm-kmp-default as component of SUSE Linux Enterprise High Performance Computing 12 SP5
  • gfs2-kmp-default as component of SUSE Linux Enterprise High Performance Computing 12 SP5
  • kernel-default as component of SUSE Linux Enterprise High Performance Computing 12 SP5
  • kernel-default-base as component of SUSE Linux Enterprise High Performance Computing 12 SP5
Summary
In the Linux kernel, the following vulnerability has been resolved: xfrm: always flush state and policy upon NETDEV_UNREGISTER event syzbot is reporting that "struct xfrm_state" refcount is leaking. unregister_netdevice: waiting for netdevsim0 to become free. Usage count = 2 ref_tracker: netdev@ffff888052f24618 has 1/1 users at __netdev_tracker_alloc include/linux/netdevice.h:4400 [inline] netdev_tracker_alloc include/linux/netdevice.h:4412 [inline] xfrm_dev_state_add+0x3a5/0x1080 net/xfrm/xfrm_device.c:316 xfrm_state_construct net/xfrm/xfrm_user.c:986 [inline] xfrm_add_sa+0x34ff/0x5fa0 net/xfrm/xfrm_user.c:1022 xfrm_user_rcv_msg+0x58e/0xc00 net/xfrm/xfrm_user.c:3507 netlink_rcv_skb+0x158/0x420 net/netlink/af_netlink.c:2550 xfrm_netlink_rcv+0x71/0x90 net/xfrm/xfrm_user.c:3529 netlink_unicast_kernel net/netlink/af_netlink.c:1318 [inline] netlink_unicast+0x5aa/0x870 net/netlink/af_netlink.c:1344 netlink_sendmsg+0x8c8/0xdd0 net/netlink/af_netlink.c:1894 sock_sendmsg_nosec net/socket.c:727 [inline] __sock_sendmsg net/socket.c:742 [inline] ____sys_sendmsg+0xa5d/0xc30 net/socket.c:2592 ___sys_sendmsg+0x134/0x1d0 net/socket.c:2646 __sys_sendmsg+0x16d/0x220 net/socket.c:2678 do_syscall_x64 arch/x86/entry/syscall_64.c:63 [inline] do_syscall_64+0xcd/0xf80 arch/x86/entry/syscall_64.c:94 entry_SYSCALL_64_after_hwframe+0x77/0x7f This is because commit d77e38e612a0 ("xfrm: Add an IPsec hardware offloading API") implemented xfrm_dev_unregister() as no-op despite xfrm_dev_state_add() from xfrm_state_construct() acquires a reference to "struct net_device". I guess that that commit expected that NETDEV_DOWN event is fired before NETDEV_UNREGISTER event fires, and also assumed that xfrm_dev_state_add() is called only if (dev->features & NETIF_F_HW_ESP) != 0. Sabrina Dubroca identified steps to reproduce the same symptoms as below. echo 0 > /sys/bus/netdevsim/new_device dev=$(ls -1 /sys/bus/netdevsim/devices/netdevsim0/net/) ip xfrm state add src 192.168.13.1 dst 192.168.13.2 proto esp \ spi 0x1000 mode tunnel aead 'rfc4106(gcm(aes))' $key 128 \ offload crypto dev $dev dir out ethtool -K $dev esp-hw-offload off echo 0 > /sys/bus/netdevsim/del_device Like these steps indicate, the NETIF_F_HW_ESP bit can be cleared after xfrm_dev_state_add() acquired a reference to "struct net_device". Also, xfrm_dev_state_add() does not check for the NETIF_F_HW_ESP bit when acquiring a reference to "struct net_device". Commit 03891f820c21 ("xfrm: handle NETDEV_UNREGISTER for xfrm device") re-introduced the NETDEV_UNREGISTER event to xfrm_dev_event(), but that commit for unknown reason chose to share xfrm_dev_down() between the NETDEV_DOWN event and the NETDEV_UNREGISTER event. I guess that that commit missed the behavior in the previous paragraph. Therefore, we need to re-introduce xfrm_dev_unregister() in order to release the reference to "struct net_device" by unconditionally flushing state and policy.
Remediation
To install this SUSE Security Update use the SUSE recommended installation methods like YaST online_update or "zypper patch".
Optional official sources

National CERT insights
?CERT means Computer Emergency Response Team; CSIRT is the closely related term Computer Security Incident Response Team.

Choose official national sources for this report. Each advisory shows its original language. Your selection is remembered on this device and included in shared links.

Official European source

ENISA European Vulnerability Database

Official EUVD identifiers, advisory evidence and known-exploited context. Missing fields are not treated as evidence of low risk.

1 current
ENISA EUVD identifier

EUVD-2026-27728

No EUVD known-exploited evidence

ENISA has published the identifier mapping but no EUVD description has been stored yet.

EUVD state
Present in the current official mapping
Known exploitation
Not present in the current ENISA EUVD known-exploited dataset. This is not proof of no exploitation.
ENISA score
Not supplied in the stored EUVD record
Advisory evidence
No linked advisory details stored yet
Recommended actionPatch only the product branches with a verified fix

Medium technical severity with no CISA KEV confirmation; remediate through the normal risk-based patch cycle unless local exposure raises the priority. Verified remediation exists for at least one product or source, but 21 structured product or package states remain unresolved. Apply remediation only to the exact product branch confirmed by its source.

Fix availability varies by product
01

What, why and how

In the Linux kernel, the following vulnerability has been resolved: xfrm: always flush state and policy upon NETDEV_UNREGISTER event syzbot is reporting that "struct xfrm_state" refcount is leaking. unregister_netdevice: waiting for netdevsim0 to become free. Usage count = 2 ref_tracker: netdev@ffff888052f24618 has 1/1 users at __netdev_tracker_alloc include/linux/netdevice.h:4400 [inline] netdev_tracker_alloc include/linux/netdevice.h:4412 [inline] xfrm_dev_state_add+0x3a5/0x1080 net/xfrm/xfrm_device.c:316 xfrm_state_construct net/xfrm/xfrm_user.c:986 [inline] xfrm_add_sa+0x34ff/0x5fa0 net/xfrm/xfrm_user.c:1022 xfrm_user_rcv_msg+0x58e/0xc00 net/xfrm/xfrm_user.c:3507 netlink_rcv_skb+0x158/0x420 net/netlink/af_netlink.c:2550 xfrm_netlink_rcv+0x71/0x90 net/xfrm/xfrm_user.c:3529 netlink_unicast_kernel net/netlink/af_netlink.c:1318 [inline] netlink_unicast+0x5aa/0x870 net/netlink/af_netlink.c:1344 netlink_sendmsg+0x8c8/0xdd0 net/netlink/af_netlink.c:1894 sock_sendmsg_nosec net/socket.c:727 [inline] __sock_sendmsg net/socket.c:742 [inline] ____sys_sendmsg+0xa5d/0xc30 net/socket.c:2592 ___sys_sendmsg+0x134/0x1d0 net/socket.c:2646 __sys_sendmsg+0x16d/0x220 net/socket.c:2678 do_syscall_x64 arch/x86/entry/syscall_64.c:63 [inline] do_syscall_64+0xcd/0xf80 arch/x86/entry/syscall_64.c:94 entry_SYSCALL_64_after_hwframe+0x77/0x7f This is because commit d77e38e612a0 ("xfrm: Add an IPsec hardware offloading API") implemented xfrm_dev_unregister() as no-op despite xfrm_dev_state_add() from xfrm_state_construct() acquires a reference to "struct net_device". I guess that that commit expected that NETDEV_DOWN event is fired before NETDEV_UNREGISTER event fires, and also assumed that xfrm_dev_state_add() is called only if (dev->features & NETIF_F_HW_ESP) != 0. Sabrina Dubroca identified steps to reproduce the same symptoms as below. echo 0 > /sys/bus/netdevsim/new_device dev=$(ls -1 /sys/bus/netdevsim/devices/netdevsim0/net/) ip xfrm state add src 192.168.13.1 dst 192.168.13.2 proto esp \ spi 0x1000 mode tunnel aead 'rfc4106(gcm(aes))' $key 128 \ offload crypto dev $dev dir out ethtool -K $dev esp-hw-offload off echo 0 > /sys/bus/netdevsim/del_device Like these steps indicate, the NETIF_F_HW_ESP bit can be cleared after xfrm_dev_state_add() acquired a reference to "struct net_device". Also, xfrm_dev_state_add() does not check for the NETIF_F_HW_ESP bit when acquiring a reference to "struct net_device". Commit 03891f820c21 ("xfrm: handle NETDEV_UNREGISTER for xfrm device") re-introduced the NETDEV_UNREGISTER event to xfrm_dev_event(), but that commit for unknown reason chose to share xfrm_dev_down() between the NETDEV_DOWN event and the NETDEV_UNREGISTER event. I guess that that commit missed the behavior in the previous paragraph. Therefore, we need to re-introduce xfrm_dev_unregister() in order to release the reference to "struct net_device" by unconditionally flushing state and policy.

What

In the Linux kernel, the following vulnerability has been resolved: xfrm: always flush state and policy upon NETDEV_UNREGISTER event syzbot is reporting that "struct xfrm_state" refcount is leaking. unregister_netdevice: waiting for netdevsim0 to become free. Usage count = 2 ref_tracker: netdev@ffff888052f24618 has 1/1 users at __netdev_tracker_alloc include/linux/netdevice.h:4400 [inline] netdev_tracker_alloc include/linux/netdevice.h:4412 [inline] xfrm_dev_state_add+0x3a5/0x1080 net/xfrm/xfrm_device.c:316 xfrm_state_construct net/xfrm/xfrm_user.c:986 [inline] xfrm_add_sa+0x34ff/0x5fa0 net/xfrm/xfrm_user.c:1022 xfrm_user_rcv_msg+0x58e/0xc00 net/xfrm/xfrm_user.c:3507 netlink_rcv_skb+0x158/0x420 net/netlink/af_netlink.c:2550 xfrm_netlink_rcv+0x71/0x90 net/xfrm/xfrm_user.c:3529 netlink_unicast_kernel net/netlink/af_netlink.c:1318 [inline] netlink_unicast+0x5aa/0x870 net/netlink/af_netlink.c:1344 netlink_sendmsg+0x8c8/0xdd0 net/netlink/af_netlink.c:1894 sock_sendmsg_nosec net/socket.c:727 [inline] __sock_sendmsg net/socket.c:742 [inline] ____sys_sendmsg+0xa5d/0xc30 net/socket.c:2592 ___sys_sendmsg+0x134/0x1d0 net/socket.c:2646 __sys_sendmsg+0x16d/0x220 net/socket.c:2678 do_syscall_x64 arch/x86/entry/syscall_64.c:63 [inline] do_syscall_64+0xcd/0xf80 arch/x86/entry/syscall_64.c:94 entry_SYSCALL_64_after_hwframe+0x77/0x7f This is because commit d77e38e612a0 ("xfrm: Add an IPsec hardware offloading API") implemented xfrm_dev_unregister() as no-op despite xfrm_dev_state_add() from xfrm_state_construct() acquires a reference to "struct net_device". I guess that that commit expected that NETDEV_DOWN event is fired before NETDEV_UNREGISTER event fires, and also assumed that xfrm_dev_state_add() is called only if (dev->features & NETIF_F_HW_ESP) != 0. Sabrina Dubroca identified steps to reproduce the same symptoms as below. echo 0 > /sys/bus/netdevsim/new_device dev=$(ls -1 /sys/bus/netdevsim/devices/netdevsim0/net/) ip xfrm state add src 192.168.13.1 dst 192.168.13.2 proto esp \ spi 0x1000 mode tunnel aead 'rfc4106(gcm(aes))' $key 128 \ offload crypto dev $dev dir out ethtool -K $dev esp-hw-offload off echo 0 > /sys/bus/netdevsim/del_device Like these steps indicate, the NETIF_F_HW_ESP bit can be cleared after xfrm_dev_state_add() acquired a reference to "struct net_device". Also, xfrm_dev_state_add() does not check for the NETIF_F_HW_ESP bit when acquiring a reference to "struct net_device". Commit 03891f820c21 ("xfrm: handle NETDEV_UNREGISTER for xfrm device") re-introduced the NETDEV_UNREGISTER event to xfrm_dev_event(), but that commit for unknown reason chose to share xfrm_dev_down() between the NETDEV_DOWN event and the NETDEV_UNREGISTER event. I guess that that commit missed the behavior in the previous paragraph. Therefore, we need to re-introduce xfrm_dev_unregister() in order to release the reference to "struct net_device" by unconditionally flushing state and policy.

Why

The current structured CVE record identifies a security weakness, but the root cause requires confirmation in the linked vendor material.

How

An attacker operating through local access may attempt exploitation with low privileges. If successful, the issue may cause the confidentiality, integrity or availability impact described by the vendor.

What

In the Linux kernel, the following vulnerability has been resolved: xfrm: always flush state and policy upon NETDEV_UNREGISTER event syzbot is reporting that "struct xfrm_state" refcount is leaking. unregister_netdevice: waiting for netdevsim0 to become free. Usage count = 2 ref_tracker: netdev@ffff888052f24618 has 1/1 users at __netdev_tracker_alloc include/linux/netdevice.h:4400 [inline] netdev_tracker_alloc include/linux/netdevice.h:4412 [inline] xfrm_dev_state_add+0x3a5/0x1080 net/xfrm/xfrm_device.c:316 xfrm_state_construct net/xfrm/xfrm_user.c:986 [inline] xfrm_add_sa+0x34ff/0x5fa0 net/xfrm/xfrm_user.c:1022 xfrm_user_rcv_msg+0x58e/0xc00 net/xfrm/xfrm_user.c:3507 netlink_rcv_skb+0x158/0x420 net/netlink/af_netlink.c:2550 xfrm_netlink_rcv+0x71/0x90 net/xfrm/xfrm_user.c:3529 netlink_unicast_kernel net/netlink/af_netlink.c:1318 [inline] netlink_unicast+0x5aa/0x870 net/netlink/af_netlink.c:1344 netlink_sendmsg+0x8c8/0xdd0 net/netlink/af_netlink.c:1894 sock_sendmsg_nosec net/socket.c:727 [inline] __sock_sendmsg net/socket.c:742 [inline] ____sys_sendmsg+0xa5d/0xc30 net/socket.c:2592 ___sys_sendmsg+0x134/0x1d0 net/socket.c:2646 __sys_sendmsg+0x16d/0x220 net/socket.c:2678 do_syscall_x64 arch/x86/entry/syscall_64.c:63 [inline] do_syscall_64+0xcd/0xf80 arch/x86/entry/syscall_64.c:94 entry_SYSCALL_64_after_hwframe+0x77/0x7f This is because commit d77e38e612a0 ("xfrm: Add an IPsec hardware offloading API") implemented xfrm_dev_unregister() as no-op despite xfrm_dev_state_add() from xfrm_state_construct() acquires a reference to "struct net_device". I guess that that commit expected that NETDEV_DOWN event is fired before NETDEV_UNREGISTER event fires, and also assumed that xfrm_dev_state_add() is called only if (dev->features & NETIF_F_HW_ESP) != 0. Sabrina Dubroca identified steps to reproduce the same symptoms as below. echo 0 > /sys/bus/netdevsim/new_device dev=$(ls -1 /sys/bus/netdevsim/devices/netdevsim0/net/) ip xfrm state add src 192.168.13.1 dst 192.168.13.2 proto esp \ spi 0x1000 mode tunnel aead 'rfc4106(gcm(aes))' $key 128 \ offload crypto dev $dev dir out ethtool -K $dev esp-hw-offload off echo 0 > /sys/bus/netdevsim/del_device Like these steps indicate, the NETIF_F_HW_ESP bit can be cleared after xfrm_dev_state_add() acquired a reference to "struct net_device". Also, xfrm_dev_state_add() does not check for the NETIF_F_HW_ESP bit when acquiring a reference to "struct net_device". Commit 03891f820c21 ("xfrm: handle NETDEV_UNREGISTER for xfrm device") re-introduced the NETDEV_UNREGISTER event to xfrm_dev_event(), but that commit for unknown reason chose to share xfrm_dev_down() between the NETDEV_DOWN event and the NETDEV_UNREGISTER event. I guess that that commit missed the behavior in the previous paragraph. Therefore, we need to re-introduce xfrm_dev_unregister() in order to release the reference to "struct net_device" by unconditionally flushing state and policy.

Why

The current structured CVE record identifies a security weakness, but the root cause requires confirmation in the linked vendor material.

How

An attacker operating through local access may attempt exploitation with low privileges. If successful, the issue may cause the confidentiality, integrity or availability impact described by the vendor.

02

Exploit reality and attack path

CVSS severity, EPSS forecast probability, public exploit material and CISA-confirmed exploitation are separate signals.

Observed exploitation
?Confirmed exploitation and public exploit material are separate signals. Attacks can occur without public proof-of-concept or exploit code.
No confirmed evidence

No CISA KEV match was present at the last successful refresh. This means no confirmation from that source, not proof of no exploitation.

Public PoC / exploit material
?Confirmed exploitation and public exploit material are separate signals. Attacks can occur without public proof-of-concept or exploit code.
None recorded

No exploit-tagged reference or CISA SSVC proof-of-concept state is currently recorded. Research may still exist outside the structured feeds.

Likely attack path
local access → vulnerable operation → cause the confidentiality, integrity or availability impact described by the vendor
Attack surface
Local
Privileges required
Low: a basic authenticated account is required
User interaction
None
Attack complexity
Low: no specialised conditions are recorded
Security boundary
Unchanged: impact remains within the vulnerable component's security authority
Weakness
?CWE means Common Weakness Enumeration.
CWE not yet assigned
CVSS vector
?CVSS means Common Vulnerability Scoring System. The vector records the metric values used to calculate technical severity.
CVSS:3.1/AV:L/AC:L/PR:L/UI:N/S:U/C:N/I:N/A:H

Common Vulnerability Scoring System 3.1: the compact vector below is decoded into plain language.

AVLocalAttack vector: The attacker needs local access to the vulnerable system.ACLowAttack complexity: No specialised conditions are required beyond attacker-controlled input.PRLowPrivileges required: The attacker needs basic user-level privileges.UINoneUser interaction: No action by another user is required.SUnchangedScope: The security impact remains within the vulnerable component's authority.CNoneConfidentiality impact: No direct loss is represented by this metric.INoneIntegrity impact: No direct loss is represented by this metric.AHighAvailability impact: A successful attack can cause a major loss.
Post-exploitation / living off the land
The issue can support a local privilege or sandbox boundary transition; normal system utilities may then be available in the gained context.
A

Official authority intelligence

Only matched European and national findings are included. Language selectors and unavailable sources are omitted.

BSI · German · WID-SEC-2026-1405Linux Kernel: Mehrere Schwachstellen

Ein Angreifer kann mehrere Schwachstellen im Linux Kernel ausnutzen, um nicht spezifizierte Angriffe durchzuführen, möglicherweise Sicherheitsmaßnahmen zu umgehen, Daten zu manipulieren oder offenzulegen oder einen Denial-of-Service-Zustand zu verursachen.

Official advisory ↗
CERT-FR · French · CERTFR-2026-AVI-0956Multiples vulnérabilités dans le noyau Linux de SUSE

d?id=CVE-2026-43124 Référence CVE CVE-2026-43128 https://www.cve.org/CVERecord?id=CVE-2026-43128 Référence CVE CVE-2026-43130 https://www.cve.org/CVERecord?id=CVE-2026-43130 Référence CVE CVE-2026-43132 https://www.cve.org/CVERecord?id=CVE-2026-43132 Référence CVE CVE-2026-43139 https://www.cve.org/CVERecord?id=CVE-2026-43139 Référence CVE CVE-2026-43145 https://www.cve.org/CVERecord?id=CVE-2026-43145 Référence CVE CVE-2026-43157 https://www.cve.org/CVERecord?id=CVE-2026-43157 Référence CVE CVE-2026-43158 https://www.cve.org/CVERecord?id=CVE-2026-43158 Référence CVE CVE-2026-43161 https://www.cve.org/CVERecord?id=CVE-2026-43161 Référence CVE CVE-2026-43167 https://www.cve.org/CVERecord?id=CVE-2026-43167 Référence CVE CVE-2026-43171 https://www.cve.org/CVERecord?id=CVE-2026-43171 Référence CVE CVE-2026-43175 https://www.cve.org/CVERecord?id=CVE-2026-43175 Référence CVE CVE-2026-43187 https://www.cve.org/CVERecord?id=CVE-2026-43187 Référence CVE CVE-2026-43190 https://www.cve.org/CVERecord?id=CVE-2026-43190 Référence CVE CVE-2026-43191 https://www.cve.org/CVERecord?id=CVE-2026-43191 Référence CVE CVE-2026-43194 https://www.cve.org/CVERecord?id=CVE-2026-43194 Référence CVE CVE-2026-43198 https://www.cve.org/CVERecord?id=CVE-2026-43198 Référence CVE CVE-2026-43199 https://www.cve.org/CVERecord?id=

Official advisory ↗
CERT-FR · French · CERTFR-2026-AVI-0954Multiples vulnérabilités dans le noyau Linux d'Ubuntu

d?id=CVE-2026-43150 Référence CVE CVE-2026-43152 https://www.cve.org/CVERecord?id=CVE-2026-43152 Référence CVE CVE-2026-43153 https://www.cve.org/CVERecord?id=CVE-2026-43153 Référence CVE CVE-2026-43156 https://www.cve.org/CVERecord?id=CVE-2026-43156 Référence CVE CVE-2026-43157 https://www.cve.org/CVERecord?id=CVE-2026-43157 Référence CVE CVE-2026-43158 https://www.cve.org/CVERecord?id=CVE-2026-43158 Référence CVE CVE-2026-43159 https://www.cve.org/CVERecord?id=CVE-2026-43159 Référence CVE CVE-2026-43162 https://www.cve.org/CVERecord?id=CVE-2026-43162 Référence CVE CVE-2026-43163 https://www.cve.org/CVERecord?id=CVE-2026-43163 Référence CVE CVE-2026-43167 https://www.cve.org/CVERecord?id=CVE-2026-43167 Référence CVE CVE-2026-43168 https://www.cve.org/CVERecord?id=CVE-2026-43168 Référence CVE CVE-2026-43169 https://www.cve.org/CVERecord?id=CVE-2026-43169 Référence CVE CVE-2026-43170 https://www.cve.org/CVERecord?id=CVE-2026-43170 Référence CVE CVE-2026-43171 https://www.cve.org/CVERecord?id=CVE-2026-43171 Référence CVE CVE-2026-43173 https://www.cve.org/CVERecord?id=CVE-2026-43173 Référence CVE CVE-2026-43175 https://www.cve.org/CVERecord?id=CVE-2026-43175 Référence CVE CVE-2026-43180 https://www.cve.org/CVERecord?id=CVE-2026-43180 Référence CVE CVE-2026-43182 https://www.cve.org/CVERecord?id=

Official advisory ↗
CERT-FR · French · CERTFR-2026-AVI-0927Multiples vulnérabilités dans le noyau Linux de SUSE

d?id=CVE-2026-43147 Référence CVE CVE-2026-43149 https://www.cve.org/CVERecord?id=CVE-2026-43149 Référence CVE CVE-2026-43152 https://www.cve.org/CVERecord?id=CVE-2026-43152 Référence CVE CVE-2026-43156 https://www.cve.org/CVERecord?id=CVE-2026-43156 Référence CVE CVE-2026-43157 https://www.cve.org/CVERecord?id=CVE-2026-43157 Référence CVE CVE-2026-43158 https://www.cve.org/CVERecord?id=CVE-2026-43158 Référence CVE CVE-2026-43159 https://www.cve.org/CVERecord?id=CVE-2026-43159 Référence CVE CVE-2026-43161 https://www.cve.org/CVERecord?id=CVE-2026-43161 Référence CVE CVE-2026-43162 https://www.cve.org/CVERecord?id=CVE-2026-43162 Référence CVE CVE-2026-43167 https://www.cve.org/CVERecord?id=CVE-2026-43167 Référence CVE CVE-2026-43169 https://www.cve.org/CVERecord?id=CVE-2026-43169 Référence CVE CVE-2026-43171 https://www.cve.org/CVERecord?id=CVE-2026-43171 Référence CVE CVE-2026-43175 https://www.cve.org/CVERecord?id=CVE-2026-43175 Référence CVE CVE-2026-43177 https://www.cve.org/CVERecord?id=CVE-2026-43177 Référence CVE CVE-2026-43180 https://www.cve.org/CVERecord?id=CVE-2026-43180 Référence CVE CVE-2026-43182 https://www.cve.org/CVERecord?id=CVE-2026-43182 Référence CVE CVE-2026-43183 https://www.cve.org/CVERecord?id=CVE-2026-43183 Référence CVE CVE-2026-43187 https://www.cve.org/CVERecord?id=

Official advisory ↗
CERT-FR · French · CERTFR-2026-AVI-0861Multiples vulnérabilités dans le noyau Linux d'Ubuntu

d?id=CVE-2026-43149 Référence CVE CVE-2026-43150 https://www.cve.org/CVERecord?id=CVE-2026-43150 Référence CVE CVE-2026-43152 https://www.cve.org/CVERecord?id=CVE-2026-43152 Référence CVE CVE-2026-43153 https://www.cve.org/CVERecord?id=CVE-2026-43153 Référence CVE CVE-2026-43156 https://www.cve.org/CVERecord?id=CVE-2026-43156 Référence CVE CVE-2026-43157 https://www.cve.org/CVERecord?id=CVE-2026-43157 Référence CVE CVE-2026-43158 https://www.cve.org/CVERecord?id=CVE-2026-43158 Référence CVE CVE-2026-43159 https://www.cve.org/CVERecord?id=CVE-2026-43159 Référence CVE CVE-2026-43163 https://www.cve.org/CVERecord?id=CVE-2026-43163 Référence CVE CVE-2026-43167 https://www.cve.org/CVERecord?id=CVE-2026-43167 Référence CVE CVE-2026-43168 https://www.cve.org/CVERecord?id=CVE-2026-43168 Référence CVE CVE-2026-43169 https://www.cve.org/CVERecord?id=CVE-2026-43169 Référence CVE CVE-2026-43170 https://www.cve.org/CVERecord?id=CVE-2026-43170 Référence CVE CVE-2026-43171 https://www.cve.org/CVERecord?id=CVE-2026-43171 Référence CVE CVE-2026-43173 https://www.cve.org/CVERecord?id=CVE-2026-43173 Référence CVE CVE-2026-43175 https://www.cve.org/CVERecord?id=CVE-2026-43175 Référence CVE CVE-2026-43180 https://www.cve.org/CVERecord?id=CVE-2026-43180 Référence CVE CVE-2026-43182 https://www.cve.org/CVERecord?id=

Official advisory ↗
CERT-FR · French · CERTFR-2026-AVI-0831Multiples vulnérabilités dans le noyau Linux d'Ubuntu

d?id=CVE-2026-43149 Référence CVE CVE-2026-43150 https://www.cve.org/CVERecord?id=CVE-2026-43150 Référence CVE CVE-2026-43152 https://www.cve.org/CVERecord?id=CVE-2026-43152 Référence CVE CVE-2026-43153 https://www.cve.org/CVERecord?id=CVE-2026-43153 Référence CVE CVE-2026-43156 https://www.cve.org/CVERecord?id=CVE-2026-43156 Référence CVE CVE-2026-43157 https://www.cve.org/CVERecord?id=CVE-2026-43157 Référence CVE CVE-2026-43158 https://www.cve.org/CVERecord?id=CVE-2026-43158 Référence CVE CVE-2026-43159 https://www.cve.org/CVERecord?id=CVE-2026-43159 Référence CVE CVE-2026-43163 https://www.cve.org/CVERecord?id=CVE-2026-43163 Référence CVE CVE-2026-43167 https://www.cve.org/CVERecord?id=CVE-2026-43167 Référence CVE CVE-2026-43168 https://www.cve.org/CVERecord?id=CVE-2026-43168 Référence CVE CVE-2026-43169 https://www.cve.org/CVERecord?id=CVE-2026-43169 Référence CVE CVE-2026-43170 https://www.cve.org/CVERecord?id=CVE-2026-43170 Référence CVE CVE-2026-43171 https://www.cve.org/CVERecord?id=CVE-2026-43171 Référence CVE CVE-2026-43173 https://www.cve.org/CVERecord?id=CVE-2026-43173 Référence CVE CVE-2026-43175 https://www.cve.org/CVERecord?id=CVE-2026-43175 Référence CVE CVE-2026-43180 https://www.cve.org/CVERecord?id=CVE-2026-43180 Référence CVE CVE-2026-43182 https://www.cve.org/CVERecord?id=

Official advisory ↗
JVN iPedia · Japanese · JVNDB-2026-015613LinuxのLinux Kernelにおける不特定の脆弱性

Linuxカーネルにおいて、以下の脆弱性が修正されました。xfrm: NETDEV_UNREGISTERイベント発生時に常に状態とポリシーをフラッシュします。syzbotは「struct xfrm_state」の参照カウントがリークしていることを報告しています。unregister_netdevice: netdevsim0が解放されるのを待機中であり、使用カウントは2です。ref_tracker: netdev@ffff888052f24618は1/1のユーザーを持っています。これは、コミットd77e38e612a0（"xfrm: Add an IPsec hardware offloading API"）がxfrm_dev_unregister()を実質的に無操作として実装したためであり、xfrm_dev_state_add()がxfrm_state_construct()から"struct net_device"への参照を取得しているにもかかわらずです。このコミットは、NETDEV_DOWNイベントがNETDEV_UNREGISTERイベントの前に発生すると想定し、さらにxfrm_dev_state_add()が(dev-features & NETIF_F_HW_ESP) != 0の場合にのみ呼ばれることを想定していたと推測されます。Sabrina Dubrocaは同様の症状を再現する手順を特定しました。これらの手順によれば、xfrm_dev_state_add()が"struct net_device"への参照を取得した後にNETIF_F_HW_ESPビットがクリアされる可能性があります。また、xfrm_dev_state_add()は参照取得時にNETIF_F_HW_ESPビットをチェックしていません。コミット03891f820c21（"xfrm: handle NETDEV_UNREGISTER for xfrm device"）はxfrm_dev_event()にNETDEV_UNREGISTERイベントを再導入しましたが、その際に、NETDEV_DOWNイベントとNETDEV_UNREGISTERイベントの両方にxfrm_dev_down()を共有させるという理由不明の選択をしました。このコミットは前述の挙動を見落としていると考えられます。したがって、状態とポリシーを無条件にフラッシュし、"struct net_device"への参照を解放するために、xfrm_dev_unregister()を再導入する必要があります。

Official advisory ↗
03

Patch and workaround

Operational remediation based on structured source evidence.

Status
?Patch availability is based on structured fixed-version fields and authoritative update references. If no fix is verified, check the vendor advisory before making a change.
Fix availability varies by product
Affected
Fixed
Linux: < 4.12, 6.6.128 ≤ 6.6.*, 6.12.75 ≤ 6.12.*, 6.18.16 ≤ 6.18.*, 6.19.6 ≤ 6.19.*, 7.0 ≤ *
Action
Use the product-specific evidence above. Patch only products with a verified fixed release, and keep every affected or under-investigation state without a matching fix in the remediation queue.
Workaround
No verified workaround is recorded. Limit untrusted access and use least privilege until authoritative guidance is available.
04

Evidence and provenance

Published 6 May 2026 · Last source change 11 May 2026, 22:19 UTC · CWE not yet assigned

CVE recordCVE.org · 5.2
CVSS sourceNIST NVD
EPSS source
?The date BlackTree first stored a score for this CVE from the daily FIRST EPSS feed.
FIRST · tracked since 2026-08-14
European sourceENISA EUVD · EUVD-2026-27728
Product sourceVendor CSAF · SUSE Product Security Team
Remediation sourceVendor CSAF · SUSE Product Security Team
CWE sourceUnavailable
NVD statusNVD enriched

Missing structured fields: CWE classification. Missing data is not evidence of low risk; review the primary advisory.

Material change intelligence

What changed after publication

View recent updates ↗

No material field changes have been recorded since change tracking began. Routine source refreshes and cosmetic edits are intentionally excluded.

Material fields only · duplicate refreshes suppressed · history retained for the configured operational retention period
CVE published
Fixed release or patch reference recorded
ENISA EUVD · EUVD-2026-27728↗Vendor CSAF · SUSE Product Security Team↗CVE authority or vendor reference↗Patch or update reference↗Patch or update reference↗Patch or update reference↗Official CVE record (CNA and ADP data)↗NVD record↗
Technical terms and abbreviations used in this report
CVE
Common Vulnerabilities and Exposures: the public identifier for one disclosed vulnerability.
CVSS
Common Vulnerability Scoring System: a technical severity framework; it is not patching priority by itself.
EPSS
Exploit Prediction Scoring System: FIRST's estimate of the probability that exploitation activity will be observed in the next 30 days; it is a forecast, not confirmation.
CWE
Common Weakness Enumeration: the standard category describing the underlying software or hardware weakness.
CNA
CVE Numbering Authority: an organisation authorised to assign and publish CVE records.
CISA ADP
Cybersecurity and Infrastructure Security Agency Authorized Data Publisher: structured enrichment added to a CVE record.
NVD
National Vulnerability Database: NIST's enrichment service for CVE records.
CERT / CSIRT
A computer security incident response team that publishes warnings or coordinates incident response.
PoC
Proof of concept: public material that demonstrates or helps reproduce exploitation.
CSAF
Common Security Advisory Framework: a machine-readable format for security advisories.
LoTL
Living off the land: abuse of legitimate tools or system functions during an attack.
Free version - for non-commercial use only.CVE-2026-43167 · cve.blacktree.nl