# CVE-2026-43234: team: avoid NETDEV_CHANGEMTU event when unregistering slave CVE-2026-43234 is fixed in 36 products on 1 platform, first by ALAS2023-2026-1702, released May 11, 2026. It is not reported as exploited. Patch Radar priority: Routine. - Web page: https://patchblox.com/security/cve/CVE-2026-43234 - Priority: Routine - CVSS: 5.5 (Moderate) - EPSS: 0.0016 - CISA KEV: not listed - Exploited (vendor report): no - Publicly disclosed: no - Published: May 6, 2026 - Vendor advisory: https://msrc.microsoft.com/update-guide/vulnerability/CVE-2026-43234 ## Description 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.c:4072 rtnetlink_rcv_msg+0x7d5/0xbe0 net/core/rtnetlink.c:6958 netlink_rcv_skb+0x232/0x4b0 net/netlink/af_netlink.c:2550 netlink_unicast_kernel net/netlink/af_netlink.c:1318 [inline] netlink_unicast+0x80f/0x9b0 net/netlink/af_netlink.c:1344 netlink_sendmsg+0x813/0xb40 net/netlink/af_netlink.c:1894 problem. Ido Schimmel found steps to reproduce ip link add name team1 type team ip link add name dummy1 mtu 1499 master team1 type dummy ip netns add ns1 ip link set dev dummy1 netns ns1 ip -n ns1 link del dev dummy1 and also found that the same issue was fixed in the bond driver in commit f51048c3e07b ("bonding: avoid NETDEV_CHANGEMTU event when unregistering slave"). Let's do similar thing for the team driver, with commit ad7c7b2172c3 ("net: hold netdev instance lock during sysfs operations") and commit 303a8487a657 ("net: s/__dev_set_mtu/__netif_set_mtu/") also applied. ## Where it's fixed | Platform | Product | Fixed in | Fix | Released | |---|---|---|---|---| | Linux | bpftool6.18 amzn 2023 | 1:6.18.16-18.222.amzn2023 | [ALAS2023-2026-1702](https://patchblox.com/security/data/fix/linux/alas2023-2026-1702.md) | May 11, 2026 | | Linux | bpftool6.18-debuginfo amzn 2023 | 1:6.18.16-18.222.amzn2023 | [ALAS2023-2026-1702](https://patchblox.com/security/data/fix/linux/alas2023-2026-1702.md) | May 11, 2026 | | Linux | kernel-64kb sles 15.7 | 6.4.0-150700.53.60.1 | [SUSE-SU-2026:2482-1](https://patchblox.com/security/data/fix/linux/suse-su-2026-2482-1.md) | Jun 22, 2026 | | Linux | kernel-64kb sles 16.0 | 6.12.0-160000.34.1 | [SUSE-SU-2026:22087-1](https://patchblox.com/security/data/fix/linux/suse-su-2026-22087-1.md) | Jun 5, 2026 | | Linux | kernel-azure sles 15.7 | 6.4.0-150700.53.60.1 | [SUSE-SU-2026:2482-1](https://patchblox.com/security/data/fix/linux/suse-su-2026-2482-1.md) | Jun 22, 2026 | | Linux | kernel-azure sles 16.0 | 6.12.0-160000.34.1 | [SUSE-SU-2026:22087-1](https://patchblox.com/security/data/fix/linux/suse-su-2026-22087-1.md) | Jun 5, 2026 | | Linux | kernel-default sles 15.7 | 6.4.0-150700.53.60.1 | [SUSE-SU-2026:2482-1](https://patchblox.com/security/data/fix/linux/suse-su-2026-2482-1.md) | Jun 22, 2026 | | Linux | kernel-default sles 16.0 | 6.12.0-160000.34.1 | [SUSE-SU-2026:22087-1](https://patchblox.com/security/data/fix/linux/suse-su-2026-22087-1.md) | Jun 5, 2026 | | Linux | kernel-default-base sles 15.7 | 6.4.0-150700.53.60.1.150700.17.35.4 | [SUSE-SU-2026:2482-1](https://patchblox.com/security/data/fix/linux/suse-su-2026-2482-1.md) | Jun 22, 2026 | | Linux | kernel-default-base sles 16.0 | 6.12.0-160000.34.1.160000.2.15 | [SUSE-SU-2026:22087-1](https://patchblox.com/security/data/fix/linux/suse-su-2026-22087-1.md) | Jun 5, 2026 | | Linux | kernel-docs sles 15.7 | 6.4.0-150700.53.60.1 | [SUSE-SU-2026:2482-1](https://patchblox.com/security/data/fix/linux/suse-su-2026-2482-1.md) | Jun 22, 2026 | | Linux | kernel-docs sles 16.0 | 6.12.0-160000.34.1 | [SUSE-SU-2026:22087-1](https://patchblox.com/security/data/fix/linux/suse-su-2026-22087-1.md) | Jun 5, 2026 | | Linux | kernel-kvmsmall sles 16.0 | 6.12.0-160000.34.1 | [SUSE-SU-2026:22087-1](https://patchblox.com/security/data/fix/linux/suse-su-2026-22087-1.md) | Jun 5, 2026 | | Linux | kernel-livepatch-6.18.16-18.222 amzn 2023 | 1:1.0-0.amzn2023 | [ALAS2023-2026-1702](https://patchblox.com/security/data/fix/linux/alas2023-2026-1702.md) | May 11, 2026 | | Linux | kernel-livepatch-SLE15-SP7-RT_Update_16 sles 15.7 | 1-150700.1.5.2 | [SUSE-SU-2026:2591-1](https://patchblox.com/security/data/fix/linux/suse-su-2026-2591-1.md) | Jun 23, 2026 | | Linux | kernel-livepatch-SLE15-SP7_Update_16 sles 15.7 | 1-150700.15.3.2 | [SUSE-SU-2026:2482-1](https://patchblox.com/security/data/fix/linux/suse-su-2026-2482-1.md) | Jun 22, 2026 | | Linux | kernel-obs-build sles 15.7 | 6.4.0-150700.53.60.2 | [SUSE-SU-2026:2482-1](https://patchblox.com/security/data/fix/linux/suse-su-2026-2482-1.md) | Jun 22, 2026 | | Linux | kernel-obs-qa sles 16.0 | 6.12.0-160000.34.1 | [SUSE-SU-2026:22087-1](https://patchblox.com/security/data/fix/linux/suse-su-2026-22087-1.md) | Jun 5, 2026 | | Linux | kernel-source sles 15.7 | 6.4.0-150700.53.60.1 | [SUSE-SU-2026:2482-1](https://patchblox.com/security/data/fix/linux/suse-su-2026-2482-1.md) | Jun 22, 2026 | | Linux | kernel-source sles 16.0 | 6.12.0-160000.34.1 | [SUSE-SU-2026:22087-1](https://patchblox.com/security/data/fix/linux/suse-su-2026-22087-1.md) | Jun 5, 2026 | | Linux | kernel-syms sles 15.7 | 6.4.0-150700.53.60.1 | [SUSE-SU-2026:2482-1](https://patchblox.com/security/data/fix/linux/suse-su-2026-2482-1.md) | Jun 22, 2026 | | Linux | kernel-syms sles 16.0 | 6.12.0-160000.34.1 | [SUSE-SU-2026:22087-1](https://patchblox.com/security/data/fix/linux/suse-su-2026-22087-1.md) | Jun 5, 2026 | | Linux | kernel-zfcpdump sles 15.7 | 6.4.0-150700.53.60.1 | [SUSE-SU-2026:2482-1](https://patchblox.com/security/data/fix/linux/suse-su-2026-2482-1.md) | Jun 22, 2026 | | Linux | kernel-zfcpdump sles 16.0 | 6.12.0-160000.34.1 | [SUSE-SU-2026:22087-1](https://patchblox.com/security/data/fix/linux/suse-su-2026-22087-1.md) | Jun 5, 2026 | | Linux | kernel6.18 amzn 2023 | 1:6.18.16-18.222.amzn2023 | [ALAS2023-2026-1702](https://patchblox.com/security/data/fix/linux/alas2023-2026-1702.md) | May 11, 2026 | | Linux | kernel6.18-debuginfo amzn 2023 | 1:6.18.16-18.222.amzn2023 | [ALAS2023-2026-1702](https://patchblox.com/security/data/fix/linux/alas2023-2026-1702.md) | May 11, 2026 | | Linux | kernel6.18-debuginfo-common-aarch64 amzn 2023 | 1:6.18.16-18.222.amzn2023 | [ALAS2023-2026-1702](https://patchblox.com/security/data/fix/linux/alas2023-2026-1702.md) | May 11, 2026 | | Linux | kernel6.18-debuginfo-common-x86_64 amzn 2023 | 1:6.18.16-18.222.amzn2023 | [ALAS2023-2026-1702](https://patchblox.com/security/data/fix/linux/alas2023-2026-1702.md) | May 11, 2026 | | Linux | kernel6.18-devel amzn 2023 | 1:6.18.16-18.222.amzn2023 | [ALAS2023-2026-1702](https://patchblox.com/security/data/fix/linux/alas2023-2026-1702.md) | May 11, 2026 | | Linux | kernel6.18-headers amzn 2023 | 1:6.18.16-18.222.amzn2023 | [ALAS2023-2026-1702](https://patchblox.com/security/data/fix/linux/alas2023-2026-1702.md) | May 11, 2026 | | Linux | kernel6.18-libbpf amzn 2023 | 1:6.18.16-18.222.amzn2023 | [ALAS2023-2026-1702](https://patchblox.com/security/data/fix/linux/alas2023-2026-1702.md) | May 11, 2026 | | Linux | kernel6.18-libbpf-debuginfo amzn 2023 | 1:6.18.16-18.222.amzn2023 | [ALAS2023-2026-1702](https://patchblox.com/security/data/fix/linux/alas2023-2026-1702.md) | May 11, 2026 | | Linux | kernel6.18-libbpf-devel amzn 2023 | 1:6.18.16-18.222.amzn2023 | [ALAS2023-2026-1702](https://patchblox.com/security/data/fix/linux/alas2023-2026-1702.md) | May 11, 2026 | | Linux | kernel6.18-libbpf-static amzn 2023 | 1:6.18.16-18.222.amzn2023 | [ALAS2023-2026-1702](https://patchblox.com/security/data/fix/linux/alas2023-2026-1702.md) | May 11, 2026 | | Linux | kernel6.18-modules-extra amzn 2023 | 1:6.18.16-18.222.amzn2023 | [ALAS2023-2026-1702](https://patchblox.com/security/data/fix/linux/alas2023-2026-1702.md) | May 11, 2026 | | Linux | kernel6.18-modules-extra-common amzn 2023 | 1:6.18.16-18.222.amzn2023 | [ALAS2023-2026-1702](https://patchblox.com/security/data/fix/linux/alas2023-2026-1702.md) | May 11, 2026 | | Linux | kernel6.18-tools amzn 2023 | 1:6.18.16-18.222.amzn2023 | [ALAS2023-2026-1702](https://patchblox.com/security/data/fix/linux/alas2023-2026-1702.md) | May 11, 2026 | | Linux | kernel6.18-tools-debuginfo amzn 2023 | 1:6.18.16-18.222.amzn2023 | [ALAS2023-2026-1702](https://patchblox.com/security/data/fix/linux/alas2023-2026-1702.md) | May 11, 2026 | | Linux | kernel6.18-tools-devel amzn 2023 | 1:6.18.16-18.222.amzn2023 | [ALAS2023-2026-1702](https://patchblox.com/security/data/fix/linux/alas2023-2026-1702.md) | May 11, 2026 | | Linux | linux Debian 13.5 (trixie) | 6.12.115-2 | [DEBIAN-CVE-2026-43234](https://patchblox.com/security/data/fix/linux/debian-cve-2026-43234.md) | May 15, 2026 | | Linux | linux Debian 14 | 6.19.6-1 | [DEBIAN-CVE-2026-43234](https://patchblox.com/security/data/fix/linux/debian-cve-2026-43234.md) | May 15, 2026 | | Linux | perf6.18 amzn 2023 | 1:6.18.16-18.222.amzn2023 | [ALAS2023-2026-1702](https://patchblox.com/security/data/fix/linux/alas2023-2026-1702.md) | May 11, 2026 | | Linux | perf6.18-debuginfo amzn 2023 | 1:6.18.16-18.222.amzn2023 | [ALAS2023-2026-1702](https://patchblox.com/security/data/fix/linux/alas2023-2026-1702.md) | May 11, 2026 | | Linux | python3-perf6.18 amzn 2023 | 1:6.18.16-18.222.amzn2023 | [ALAS2023-2026-1702](https://patchblox.com/security/data/fix/linux/alas2023-2026-1702.md) | May 11, 2026 | | Linux | python3-perf6.18-debuginfo amzn 2023 | 1:6.18.16-18.222.amzn2023 | [ALAS2023-2026-1702](https://patchblox.com/security/data/fix/linux/alas2023-2026-1702.md) | May 11, 2026 | --- Data as of 2026-11-09T13:31:49Z UTC. 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