Vulnerability in Linux kernel (CVE-2026-43167)
Summary
Vulnerability in Linux kernel (CVE-2026-43167). Risk of unauthorized operations or information disclosure.
Original description
The description as published by the source.
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 commi…
Source: NIST National Vulnerability Database NVD
Auto-generated summary
Assembled by SecPulse from the source data (CVSS, CWE, affected versions) using templates — no AI involved. Check the original description and references below for exact details.
A vulnerability tracked as CVE-2026-43167 has been found in Linux kernel.
Risk of unauthorized operations or information disclosure. CVSS score: 5.5/10.
What to do: apply the vendor's official patched release.
If unsure, ask your IT team or search "Linux kernel CVE-2026-43167" on the vendor's site.
CVE-2026-43167 (Linux kernel) — CVSS v3 5.5
Attack vector: local / no user interaction
Plan: 1) Audit SBOM/dependencies, 2) Stage→prod upgrade, 3) Add WAF/proxy monitoring on affected endpoints, 4) Hunt IOCs in logs.
Refs: see the GHSA / vendor advisory / patched release linked on this page.
A vulnerability (unclassified) exists in Linux kernel.
Check the vendor advisory for the affected versions of Linux kernel.
Severity: Medium (CVSS 5.5/10). Risk of unauthorized operations or information disclosure.
Update to the patched release per vendor advisory.
Until the patch is applied: disable the affected feature, apply WAF rules, or restrict access via network ACLs.
Search webserver/proxy logs for unusual request patterns matching this CVE's known IOCs. Audit SBOM/dependencies to find affected services.
Response actions
Concrete steps and command examples for SOC/SRE teams to execute in order
-
1Identify exposure identify
Audit SBOM/dependencies for affected components.資産台帳・SBOM・依存マニフェストで Linux kernel を使っているサービスとバージョンを洗い出す。
-
2Post-deployment verification verify
Confirm patched version is live in productionパッチ適用後、ステージングで PoC または同等の悪用パターンを再現して脆弱性が閉じたことを確認。本番ではアクセスログ・WAF でアラート再発が無いか継続監視。
Affected packages
Fix status by distribution
Fixed packages published by each distribution for this CVE
- BellSoft Alpaquita BELL-CVE-2026-43167 linux-lts
- Debian DEBIAN-CVE-2026-43167 linux
- Ubuntu UBUNTU-CVE-2026-43167 linux-azure
References
- advisory github.com
- advisory nvd.nist.gov
- package git.kernel.org
- web git.kernel.org
- web git.kernel.org
- web git.kernel.org
- web git.kernel.org
- web git.kernel.org