Vulnerability in Linux kernel (CVE-2026-43234)
Summary
Vulnerability in Linux kernel (CVE-2026-43234). 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:
team: avoid NETDEV_CHANGEMTU event when unregistering slave
syzbot is reporting
unregister_netdevice: waiting for netdevsim0 to become free. Usage count = 3
ref_tracker: netdev@ffff88807dcf8618 has 1/2 users at
__netdev_tracker_alloc include/linux/netdevice.h:4400 [inline]
netdev_hold include/linux/netdevice.h:4429 [inline]
inetdev_init+0x201/0x4e0 net/ipv4/devinet.c:286
inetdev_event+0x251/0x1610 net/ipv4/devinet.c:1600
notifier_call_chain+0x19d/0x3a0 kernel/notifier.c:85
call_netdevice_notifiers_mtu net/core/dev.c:2318 [inline]
netif_set_mtu_ext+0x5aa/0x800 net/core/dev.c:9886
netif_set_mtu+0xd7/0x1b0 net/core/dev.c:9907
dev_set_mtu+0x126/0x260 net/core/dev_api.c:248
team_port_del+0xb07/0xcb0 drivers/net/team/team_core.c:1333
team_del_slave drivers/net/team/team_core.c:1936 [inline]
team_device_event+0x207/0x5b0 drivers/net/team/team_core.c:2929
notifier_call_chain+0x19d/0x3a0 kernel/notifier.c:85
call_netdevice_notifiers_extack net/core/dev.c:2281 [inline]
call_netdevice_notifiers net/core/dev.c:2295 [inline]
__dev_change_net_namespace+0xcb7/0x2050 net/core/dev.c:12592
do_setlink+0x2ce/0x4590 net/core/rtnetlink.c:3060
rtnl_changelink net/core/rtnetlink.c:3776 [inline]
__rtnl_newlink net/core/rtnetlink.c:3935 [inline]
rtnl_newlink+0x15a9/0x1be0 net/core/rtnetlink…
Source: NIST National Vulnerability Database NVD GitHub Advisory
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-2026-43234 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-2026-43234" on the vendor's site.
CVE-2026-43234 (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-2026-43234 linux-lts
- Debian DEBIAN-CVE-2026-43234 linux
- Ubuntu UBUNTU-CVE-2026-43234 linux
References
- advisory nvd.nist.gov
- advisory github.com
- package git.kernel.org
- web git.kernel.org
- web git.kernel.org
- web git.kernel.org
- web github.com