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Linux Distros Unpatched Vulnerability : CVE-2026-43167

high Nessus Plugin ID 312779

Synopsis

The Linux/Unix host has one or more packages installed with a vulnerability that the vendor indicates will not be patched.

Description

The Linux/Unix host has one or more packages installed that are impacted by a vulnerability without a vendor supplied patch available.

 - 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. (CVE-2026-43167)

Note that Nessus relies on the presence of the package as reported by the vendor.

Solution

There is no known solution at this time.

See Also

https://access.redhat.com/security/cve/cve-2026-43167

https://security-tracker.debian.org/tracker/CVE-2026-43167

Plugin Details

Severity: High

ID: 312779

File Name: unpatched_CVE_2026_43167.nasl

Version: 1.2

Type: Local

Agent: unix

Family: Misc.

Published: 5/6/2026

Updated: 5/7/2026

Supported Sensors: Nessus Agent, Nessus

Risk Information

VPR

Risk Factor: Medium

Score: 6.7

CVSS v2

Risk Factor: Medium

Base Score: 6.2

Temporal Score: 5.3

Vector: CVSS2#AV:L/AC:L/Au:S/C:N/I:C/A:C

CVSS Score Source: CVE-2026-43167

CVSS v3

Risk Factor: High

Base Score: 7.1

Temporal Score: 6.5

Vector: CVSS:3.0/AV:L/AC:L/PR:L/UI:N/S:U/C:N/I:H/A:H

Temporal Vector: CVSS:3.0/E:U/RL:U/RC:C

Vulnerability Information

CPE: cpe:/o:debian:debian_linux:11.0, cpe:/o:redhat:enterprise_linux:8, p-cpe:/a:centos:centos:kernel, p-cpe:/a:centos:centos:kernel-doc, p-cpe:/a:centos:centos:kernel-devel, p-cpe:/a:centos:centos:kernel-headers, p-cpe:/a:centos:centos:kernel-debug, p-cpe:/a:centos:centos:kernel-debug-devel, p-cpe:/a:centos:centos:perf, p-cpe:/a:centos:centos:kernel-abi-whitelists, p-cpe:/a:centos:centos:kernel-tools, p-cpe:/a:centos:centos:kernel-tools-libs, p-cpe:/a:centos:centos:kernel-tools-libs-devel, p-cpe:/a:centos:centos:bpftool, p-cpe:/a:debian:debian_linux:linux, p-cpe:/a:redhat:enterprise_linux:kernel, p-cpe:/a:redhat:enterprise_linux:kernel-debug, p-cpe:/a:redhat:enterprise_linux:kernel-debug-devel, p-cpe:/a:redhat:enterprise_linux:kernel-devel, p-cpe:/a:redhat:enterprise_linux:kernel-doc, p-cpe:/a:redhat:enterprise_linux:kernel-headers, p-cpe:/a:redhat:enterprise_linux:perf, p-cpe:/a:redhat:enterprise_linux:kernel-abi-whitelists, p-cpe:/a:redhat:enterprise_linux:kernel-rt, p-cpe:/a:redhat:enterprise_linux:kernel-rt-debug, p-cpe:/a:redhat:enterprise_linux:kernel-rt-debug-devel, p-cpe:/a:redhat:enterprise_linux:kernel-rt-devel, p-cpe:/a:redhat:enterprise_linux:kernel-tools, p-cpe:/a:redhat:enterprise_linux:kernel-tools-libs, p-cpe:/a:redhat:enterprise_linux:kernel-tools-libs-devel, p-cpe:/a:redhat:enterprise_linux:kernel-rt-core, p-cpe:/a:redhat:enterprise_linux:kernel-rt-debug-core, p-cpe:/a:redhat:enterprise_linux:kernel-rt-debug-kvm, p-cpe:/a:redhat:enterprise_linux:kernel-rt-debug-modules, p-cpe:/a:redhat:enterprise_linux:kernel-rt-debug-modules-extra, p-cpe:/a:redhat:enterprise_linux:kernel-rt-kvm, p-cpe:/a:redhat:enterprise_linux:kernel-rt-modules, p-cpe:/a:redhat:enterprise_linux:kernel-rt-modules-extra, p-cpe:/a:redhat:enterprise_linux:bpftool, p-cpe:/a:redhat:enterprise_linux:kernel-core, p-cpe:/a:redhat:enterprise_linux:kernel-cross-headers, p-cpe:/a:redhat:enterprise_linux:kernel-debug-core, p-cpe:/a:redhat:enterprise_linux:kernel-debug-modules, p-cpe:/a:redhat:enterprise_linux:kernel-debug-modules-extra, p-cpe:/a:redhat:enterprise_linux:kernel-modules, p-cpe:/a:redhat:enterprise_linux:kernel-modules-extra, p-cpe:/a:redhat:enterprise_linux:kernel-zfcpdump, p-cpe:/a:redhat:enterprise_linux:kernel-zfcpdump-core, p-cpe:/a:redhat:enterprise_linux:kernel-zfcpdump-devel, p-cpe:/a:redhat:enterprise_linux:kernel-zfcpdump-modules, p-cpe:/a:redhat:enterprise_linux:kernel-zfcpdump-modules-extra, p-cpe:/a:redhat:enterprise_linux:python3-perf, cpe:/o:centos:centos:8, p-cpe:/a:centos:centos:kernel-core, p-cpe:/a:centos:centos:kernel-cross-headers, p-cpe:/a:centos:centos:kernel-debug-core, p-cpe:/a:centos:centos:kernel-debug-modules, p-cpe:/a:centos:centos:kernel-debug-modules-extra, p-cpe:/a:centos:centos:kernel-modules, p-cpe:/a:centos:centos:kernel-modules-extra, p-cpe:/a:centos:centos:python3-perf, p-cpe:/a:redhat:enterprise_linux:kernel-abi-stablelists, p-cpe:/a:centos:centos:kernel-abi-stablelists, p-cpe:/a:redhat:enterprise_linux:kernel-debug-modules-internal, p-cpe:/a:redhat:enterprise_linux:kernel-ipaclones-internal, p-cpe:/a:redhat:enterprise_linux:kernel-modules-internal, p-cpe:/a:redhat:enterprise_linux:kernel-selftests-internal, p-cpe:/a:redhat:enterprise_linux:kernel-zfcpdump-modules-internal, p-cpe:/a:centos:centos:kernel-rt, p-cpe:/a:centos:centos:kernel-rt-core, p-cpe:/a:centos:centos:kernel-rt-debug, p-cpe:/a:centos:centos:kernel-rt-debug-core, p-cpe:/a:centos:centos:kernel-rt-debug-devel, p-cpe:/a:centos:centos:kernel-rt-debug-modules, p-cpe:/a:centos:centos:kernel-rt-debug-modules-extra, p-cpe:/a:centos:centos:kernel-rt-devel, p-cpe:/a:centos:centos:kernel-rt-modules, p-cpe:/a:centos:centos:kernel-rt-modules-extra, cpe:/o:redhat:enterprise_linux:9, p-cpe:/a:redhat:enterprise_linux:kernel-debug-devel-matched, p-cpe:/a:redhat:enterprise_linux:kernel-devel-matched, p-cpe:/a:redhat:enterprise_linux:kernel-zfcpdump-devel-matched, cpe:/o:debian:debian_linux:12.0, p-cpe:/a:redhat:enterprise_linux:kernel-rt-debug-modules-core, p-cpe:/a:redhat:enterprise_linux:kernel-rt-modules-core, p-cpe:/a:redhat:enterprise_linux:kernel-64k, p-cpe:/a:redhat:enterprise_linux:kernel-64k-core, p-cpe:/a:redhat:enterprise_linux:kernel-64k-debug, p-cpe:/a:redhat:enterprise_linux:kernel-64k-debug-core, p-cpe:/a:redhat:enterprise_linux:kernel-64k-debug-devel, p-cpe:/a:redhat:enterprise_linux:kernel-64k-debug-devel-matched, p-cpe:/a:redhat:enterprise_linux:kernel-64k-debug-modules, p-cpe:/a:redhat:enterprise_linux:kernel-64k-debug-modules-core, p-cpe:/a:redhat:enterprise_linux:kernel-64k-debug-modules-extra, p-cpe:/a:redhat:enterprise_linux:kernel-64k-devel, p-cpe:/a:redhat:enterprise_linux:kernel-64k-devel-matched, p-cpe:/a:redhat:enterprise_linux:kernel-64k-modules, p-cpe:/a:redhat:enterprise_linux:kernel-64k-modules-core, p-cpe:/a:redhat:enterprise_linux:kernel-64k-modules-extra, p-cpe:/a:redhat:enterprise_linux:kernel-debug-modules-core, p-cpe:/a:redhat:enterprise_linux:kernel-debug-uki-virt, p-cpe:/a:redhat:enterprise_linux:kernel-modules-core, p-cpe:/a:redhat:enterprise_linux:kernel-uki-virt, p-cpe:/a:redhat:enterprise_linux:kernel-zfcpdump-modules-core, p-cpe:/a:redhat:enterprise_linux:rtla, p-cpe:/a:centos:centos:kernel-rt-debug-kvm, p-cpe:/a:centos:centos:kernel-rt-kvm, p-cpe:/a:redhat:enterprise_linux:kernel-rt-debug-modules-internal, p-cpe:/a:redhat:enterprise_linux:kernel-rt-modules-internal, p-cpe:/a:redhat:enterprise_linux:kernel-rt-selftests-internal, p-cpe:/a:redhat:enterprise_linux:libperf, p-cpe:/a:redhat:enterprise_linux:rv, p-cpe:/a:redhat:enterprise_linux:kernel-64k-debug-modules-internal, p-cpe:/a:redhat:enterprise_linux:kernel-64k-debug-modules-partner, p-cpe:/a:redhat:enterprise_linux:kernel-64k-modules-internal, p-cpe:/a:redhat:enterprise_linux:kernel-64k-modules-partner, p-cpe:/a:redhat:enterprise_linux:kernel-debug-modules-partner, p-cpe:/a:redhat:enterprise_linux:kernel-modules-partner, p-cpe:/a:redhat:enterprise_linux:kernel-rt-debug-devel-matched, p-cpe:/a:redhat:enterprise_linux:kernel-rt-debug-modules-partner, p-cpe:/a:redhat:enterprise_linux:kernel-rt-devel-matched, p-cpe:/a:redhat:enterprise_linux:kernel-rt-modules-partner, p-cpe:/a:redhat:enterprise_linux:kernel-zfcpdump-modules-partner, p-cpe:/a:centos:centos:kernel-64k, p-cpe:/a:centos:centos:kernel-64k-core, p-cpe:/a:centos:centos:kernel-64k-debug, p-cpe:/a:centos:centos:kernel-64k-debug-core, p-cpe:/a:centos:centos:kernel-64k-debug-devel, p-cpe:/a:centos:centos:kernel-64k-debug-devel-matched, p-cpe:/a:centos:centos:kernel-64k-debug-modules, p-cpe:/a:centos:centos:kernel-64k-debug-modules-core, p-cpe:/a:centos:centos:kernel-64k-debug-modules-extra, p-cpe:/a:centos:centos:kernel-64k-debug-modules-internal, p-cpe:/a:centos:centos:kernel-64k-debug-modules-partner, p-cpe:/a:centos:centos:kernel-64k-devel, p-cpe:/a:centos:centos:kernel-64k-devel-matched, p-cpe:/a:centos:centos:kernel-64k-modules, p-cpe:/a:centos:centos:kernel-64k-modules-core, p-cpe:/a:centos:centos:kernel-64k-modules-extra, p-cpe:/a:centos:centos:kernel-64k-modules-internal, p-cpe:/a:centos:centos:kernel-64k-modules-partner, p-cpe:/a:centos:centos:kernel-debug-devel-matched, p-cpe:/a:centos:centos:kernel-debug-modules-core, p-cpe:/a:centos:centos:kernel-debug-modules-internal, p-cpe:/a:centos:centos:kernel-debug-modules-partner, p-cpe:/a:centos:centos:kernel-debug-uki-virt, p-cpe:/a:centos:centos:kernel-devel-matched, p-cpe:/a:centos:centos:kernel-ipaclones-internal, p-cpe:/a:centos:centos:kernel-modules-core, p-cpe:/a:centos:centos:kernel-modules-internal, p-cpe:/a:centos:centos:kernel-modules-partner, p-cpe:/a:centos:centos:kernel-rt-debug-devel-matched, p-cpe:/a:centos:centos:kernel-rt-debug-modules-core, p-cpe:/a:centos:centos:kernel-rt-debug-modules-internal, p-cpe:/a:centos:centos:kernel-rt-debug-modules-partner, p-cpe:/a:centos:centos:kernel-rt-devel-matched, p-cpe:/a:centos:centos:kernel-rt-modules-core, p-cpe:/a:centos:centos:kernel-rt-modules-internal, p-cpe:/a:centos:centos:kernel-rt-modules-partner, p-cpe:/a:centos:centos:kernel-selftests-internal, p-cpe:/a:centos:centos:kernel-uki-virt, p-cpe:/a:centos:centos:kernel-zfcpdump, p-cpe:/a:centos:centos:kernel-zfcpdump-core, p-cpe:/a:centos:centos:kernel-zfcpdump-devel, p-cpe:/a:centos:centos:kernel-zfcpdump-devel-matched, p-cpe:/a:centos:centos:kernel-zfcpdump-modules, p-cpe:/a:centos:centos:kernel-zfcpdump-modules-core, p-cpe:/a:centos:centos:kernel-zfcpdump-modules-extra, p-cpe:/a:centos:centos:kernel-zfcpdump-modules-internal, p-cpe:/a:centos:centos:kernel-zfcpdump-modules-partner, p-cpe:/a:centos:centos:libperf, p-cpe:/a:centos:centos:libperf-devel, p-cpe:/a:centos:centos:rtla, p-cpe:/a:centos:centos:rv, p-cpe:/a:centos:centos:kernel-debug-uki-virt-addons, p-cpe:/a:centos:centos:kernel-uki-virt-addons, p-cpe:/a:redhat:enterprise_linux:kernel-uki-virt-addons, p-cpe:/a:centos:centos:kernel-rt-64k, p-cpe:/a:centos:centos:kernel-rt-64k-core, p-cpe:/a:centos:centos:kernel-rt-64k-debug, p-cpe:/a:centos:centos:kernel-rt-64k-debug-core, p-cpe:/a:centos:centos:kernel-rt-64k-debug-devel, p-cpe:/a:centos:centos:kernel-rt-64k-debug-devel-matched, p-cpe:/a:centos:centos:kernel-rt-64k-debug-kvm, p-cpe:/a:centos:centos:kernel-rt-64k-debug-modules, p-cpe:/a:centos:centos:kernel-rt-64k-debug-modules-core, p-cpe:/a:centos:centos:kernel-rt-64k-debug-modules-extra, p-cpe:/a:centos:centos:kernel-rt-64k-debug-modules-internal, p-cpe:/a:centos:centos:kernel-rt-64k-debug-modules-partner, p-cpe:/a:centos:centos:kernel-rt-64k-devel, p-cpe:/a:centos:centos:kernel-rt-64k-devel-matched, p-cpe:/a:centos:centos:kernel-rt-64k-kvm, p-cpe:/a:centos:centos:kernel-rt-64k-modules, p-cpe:/a:centos:centos:kernel-rt-64k-modules-core, p-cpe:/a:centos:centos:kernel-rt-64k-modules-extra, p-cpe:/a:centos:centos:kernel-rt-64k-modules-internal, p-cpe:/a:centos:centos:kernel-rt-64k-modules-partner, p-cpe:/a:redhat:enterprise_linux:kernel-rt-64k, p-cpe:/a:redhat:enterprise_linux:kernel-rt-64k-core, p-cpe:/a:redhat:enterprise_linux:kernel-rt-64k-debug, p-cpe:/a:redhat:enterprise_linux:kernel-rt-64k-debug-core, p-cpe:/a:redhat:enterprise_linux:kernel-rt-64k-debug-devel, p-cpe:/a:redhat:enterprise_linux:kernel-rt-64k-debug-modules, p-cpe:/a:redhat:enterprise_linux:kernel-rt-64k-debug-modules-core, p-cpe:/a:redhat:enterprise_linux:kernel-rt-64k-debug-modules-extra, p-cpe:/a:redhat:enterprise_linux:kernel-rt-64k-devel, p-cpe:/a:redhat:enterprise_linux:kernel-rt-64k-modules, p-cpe:/a:redhat:enterprise_linux:kernel-rt-64k-modules-core, p-cpe:/a:redhat:enterprise_linux:kernel-rt-64k-modules-extra, cpe:/o:redhat:enterprise_linux:10, p-cpe:/a:centos:centos:kernel-rt-selftests-internal, p-cpe:/a:redhat:enterprise_linux:kernel-debug-uki-virt-addons, p-cpe:/a:redhat:enterprise_linux:kernel-rt-64k-debug-devel-matched, p-cpe:/a:redhat:enterprise_linux:kernel-rt-64k-debug-kvm, p-cpe:/a:redhat:enterprise_linux:kernel-rt-64k-debug-modules-internal, p-cpe:/a:redhat:enterprise_linux:kernel-rt-64k-debug-modules-partner, p-cpe:/a:redhat:enterprise_linux:kernel-rt-64k-devel-matched, p-cpe:/a:redhat:enterprise_linux:kernel-rt-64k-kvm, p-cpe:/a:redhat:enterprise_linux:kernel-rt-64k-modules-internal, p-cpe:/a:redhat:enterprise_linux:kernel-rt-64k-modules-partner, p-cpe:/a:redhat:enterprise_linux:libperf-devel, p-cpe:/a:redhat:enterprise_linux:kernel-modules-extra-matched, p-cpe:/a:centos:centos:kernel-modules-extra-matched

Required KB Items: Host/cpu, Host/local_checks_enabled, global_settings/vendor_unpatched, Host/OS/identifier

Exploit Ease: No known exploits are available

Vulnerability Publication Date: 5/6/2026

Reference Information

CVE: CVE-2026-43167