CVE-2026-43441

Description

In the Linux kernel, the following vulnerability has been resolved: net: bonding: Fix nd_tbl NULL dereference when IPv6 is disabled When booting with the 'ipv6.disable=1' parameter, the nd_tbl is never initialized because inet6_init() exits before ndisc_init() is called which initializes it. If bonding ARP/NS validation is enabled, an IPv6 NS/NA packet received on a slave can reach bond_validate_na(), which calls bond_has_this_ip6(). That path calls ipv6_chk_addr() and can crash in __ipv6_chk_addr_and_flags(). BUG: kernel NULL pointer dereference, address: 00000000000005d8 Oops: Oops: 0000 [#1] SMP NOPTI RIP: 0010:__ipv6_chk_addr_and_flags+0x69/0x170 Call Trace: <IRQ> ipv6_chk_addr+0x1f/0x30 bond_validate_na+0x12e/0x1d0 [bonding] ? __pfx_bond_handle_frame+0x10/0x10 [bonding] bond_rcv_validate+0x1a0/0x450 [bonding] bond_handle_frame+0x5e/0x290 [bonding] ? srso_alias_return_thunk+0x5/0xfbef5 __netif_receive_skb_core.constprop.0+0x3e8/0xe50 ? srso_alias_return_thunk+0x5/0xfbef5 ? update_cfs_rq_load_avg+0x1a/0x240 ? srso_alias_return_thunk+0x5/0xfbef5 ? __enqueue_entity+0x5e/0x240 __netif_receive_skb_one_core+0x39/0xa0 process_backlog+0x9c/0x150 __napi_poll+0x30/0x200 ? srso_alias_return_thunk+0x5/0xfbef5 net_rx_action+0x338/0x3b0 handle_softirqs+0xc9/0x2a0 do_softirq+0x42/0x60 </IRQ> <TASK> __local_bh_enable_ip+0x62/0x70 __dev_queue_xmit+0x2d3/0x1000 ? srso_alias_return_thunk+0x5/0xfbef5 ? srso_alias_return_thunk+0x5/0xfbef5 ? packet_parse_headers+0x10a/0x1a0 packet_sendmsg+0x10da/0x1700 ? kick_pool+0x5f/0x140 ? srso_alias_return_thunk+0x5/0xfbef5 ? __queue_work+0x12d/0x4f0 __sys_sendto+0x1f3/0x220 __x64_sys_sendto+0x24/0x30 do_syscall_64+0x101/0xf80 ? exc_page_fault+0x6e/0x170 ? srso_alias_return_thunk+0x5/0xfbef5 entry_SYSCALL_64_after_hwframe+0x77/0x7f </TASK> Fix this by checking ipv6_mod_enabled() before dispatching IPv6 packets to bond_na_rcv(). If IPv6 is disabled, return early from bond_rcv_validate() and avoid the path to ipv6_chk_addr().

Gravité et risque d'exploitation

CVE-2026-43441 obtient un score CVSS de 7.5/10, soit une gravité élevée. Selon le modèle EPSS, la probabilité qu'elle soit exploitée dans les 30 prochains jours est de 0.68 %, ce qui la place devant 51.6 % des CVE référencées.

Que faire ?

• Vérifiez si Linux (versions <=6.1.*, <=6.12.*, 5.18, 6.12.78, 0, 7.0, <5.18, 6.18.19, <=6.6.*, <=6.19.*, <c9c238066fb254dabf65e27379f93c56112c5b96, 6.19.9, <cf6099ef493b94e140b0fad52482a78853115318, <=6.18.*, 6.1.167, <30021e969d48e5819d5ae56936c2f34c0f7ce997, 4e24be018eb9dbcefa4b01c07e298b147dc1a4d7, <=*, <95faa1459b83fa544191e82ccc73856f03b7741f, 6.6.130, <49dbfcb70eca5f6f9043594e1e323c74c39e3863, <c78f01abe535853f13f0b26cd5b1d2f19bf52e2f) est présent sur votre parc.
• Appliquez le correctif ou la version corrigée indiqués dans les références de l'éditeur.
• À défaut de correctif, limitez l'exposition (filtrage réseau, désactivation du composant).
• Automatisez la détection : les agents CVE Heimdall (gratuits, open source) corrèlent l'inventaire de vos serveurs avec la base CVE.

Références

• https://git.kernel.org/stable/c/49dbfcb70eca5f6f9043594e1e323c74c39e3863
• https://git.kernel.org/stable/c/cf6099ef493b94e140b0fad52482a78853115318
• https://git.kernel.org/stable/c/c78f01abe535853f13f0b26cd5b1d2f19bf52e2f
• https://git.kernel.org/stable/c/95faa1459b83fa544191e82ccc73856f03b7741f
• https://git.kernel.org/stable/c/c9c238066fb254dabf65e27379f93c56112c5b96
• https://git.kernel.org/stable/c/30021e969d48e5819d5ae56936c2f34c0f7ce997