CVE-2026-23099

CVE-2026-23099 is a high-severity vulnerability in Linux Linux Kernel with a CVSS 3.x base score of 7.1. It is not currently listed as actively exploited by CISA, and its EPSS exploit-prediction score is low. The underlying weakness is classified as CWE-125.

Key facts

Description

In the Linux kernel, the following vulnerability has been resolved: bonding: limit BOND_MODE_8023AD to Ethernet devices BOND_MODE_8023AD makes sense for ARPHRD_ETHER only. syzbot reported: BUG: KASAN: global-out-of-bounds in __hw_addr_create net/core/dev_addr_lists.c:63 [inline] BUG: KASAN: global-out-of-bounds in __hw_addr_add_ex+0x25d/0x760 net/core/dev_addr_lists.c:118 Read of size 16 at addr ffffffff8bf94040 by task syz.1.3580/19497 CPU: 1 UID: 0 PID: 19497 Comm: syz.1.3580 Tainted: G L syzkaller #0 PREEMPT(full) Tainted: [L]=SOFTLOCKUP Hardware name: Google Google Compute Engine/Google Compute Engine, BIOS Google 10/25/2025 Call Trace: <TASK> dump_stack_lvl+0xe8/0x150 lib/dump_stack.c:120 print_address_description mm/kasan/report.c:378 [inline] print_report+0xca/0x240 mm/kasan/report.c:482 kasan_report+0x118/0x150 mm/kasan/report.c:595 check_region_inline mm/kasan/generic.c:-1 [inline] kasan_check_range+0x2b0/0x2c0 mm/kasan/generic.c:200 __asan_memcpy+0x29/0x70 mm/kasan/shadow.c:105 __hw_addr_create net/core/dev_addr_lists.c:63 [inline] __hw_addr_add_ex+0x25d/0x760 net/core/dev_addr_lists.c:118 __dev_mc_add net/core/dev_addr_lists.c:868 [inline] dev_mc_add+0xa1/0x120 net/core/dev_addr_lists.c:886 bond_enslave+0x2b8b/0x3ac0 drivers/net/bonding/bond_main.c:2180 do_set_master+0x533/0x6d0 net/core/rtnetlink.c:2963 do_setlink+0xcf0/0x41c0 net/core/rtnetlink.c:3165 rtnl_changelink net/core/rtnetlink.c:3776 [inline] __rtnl_newlink net/core/rtnetlink.c:3935 [inline] rtnl_newlink+0x161c/0x1c90 net/core/rtnetlink.c:4072 rtnetlink_rcv_msg+0x7cf/0xb70 net/core/rtnetlink.c:6958 netlink_rcv_skb+0x208/0x470 net/netlink/af_netlink.c:2550 netlink_unicast_kernel net/netlink/af_netlink.c:1318 [inline] netlink_unicast+0x82f/0x9e0 net/netlink/af_netlink.c:1344 netlink_sendmsg+0x805/0xb30 net/netlink/af_netlink.c:1894 sock_sendmsg_nosec net/socket.c:727 [inline] __sock_sendmsg+0x21c/0x270 net/socket.c:742 ____sys_sendmsg+0x505/0x820 net/socket.c:2592 ___sys_sendmsg+0x21f/0x2a0 net/socket.c:2646 __sys_sendmsg+0x164/0x220 net/socket.c:2678 do_syscall_32_irqs_on arch/x86/entry/syscall_32.c:83 [inline] __do_fast_syscall_32+0x1dc/0x560 arch/x86/entry/syscall_32.c:307 do_fast_syscall_32+0x34/0x80 arch/x86/entry/syscall_32.c:332 entry_SYSENTER_compat_after_hwframe+0x84/0x8e </TASK> The buggy address belongs to the variable: lacpdu_mcast_addr+0x0/0x40

Frequently asked questions

What is CVE-2026-23099?
In the Linux kernel, the following vulnerability has been resolved: bonding: limit BOND_MODE_8023AD to Ethernet devices BOND_MODE_8023AD makes sense for ARPHRD_ETHER only. syzbot reported: BUG: KASAN: global-out-of-bounds in __hw_addr_create net/core/dev_addr_lists.c:63 [inline] BUG: KASAN: global-out-of-bounds in __hw_addr_add_ex+0x25d/0x760 net/core/dev_addr_lists.c:118 Read of size 16 at addr ffffffff8bf94040 by task syz.1.3580/19497 CPU: 1 UID: 0 PID: 19497 Comm: syz.1.3580 Tainted: G L syzkaller #0 PREEMPT(full) Tainted: [L]=SOFTLOCKUP Hardware name: Google Google Compute Engine/Google Compute Engine, BIOS Google 10/25/2025 Call Trace: <TASK> dump_stack_lvl+0xe8/0x150 lib/dump_stack.c:120 print_address_description mm/kasan/report.c:378 [inline] print_report+0xca/0x240 mm/kasan/report.c:482 kasan_report+0x118/0x150 mm/kasan/report.c:595 check_region_inline mm/kasan/generic.c:-1 [inline] kasan_check_range+0x2b0/0x2c0 mm/kasan/generic.c:200 __asan_memcpy+0x29/0x70 mm/kasan/shadow.c:105 __hw_addr_create net/core/dev_addr_lists.c:63 [inline] __hw_addr_add_ex+0x25d/0x760 net/core/dev_addr_lists.c:118 __dev_mc_add net/core/dev_addr_lists.c:868 [inline] dev_mc_add+0xa1/0x120 net/core/dev_addr_lists.c:886 bond_enslave+0x2b8b/0x3ac0 drivers/net/bonding/bond_main.c:2180 do_set_master+0x533/0x6d0 net/core/rtnetlink.c:2963 do_setlink+0xcf0/0x41c0 net/core/rtnetlink.c:3165 rtnl_changelink net/core/rtnetlink.c:3776 [inline] __rtnl_newlink net/core/rtnetlink.c:3935 [inline] rtnl_newlink+0x161c/0x1c90 net/core/rtnetlink.c:4072 rtnetlink_rcv_msg+0x7cf/0xb70 net/core/rtnetlink.c:6958 netlink_rcv_skb+0x208/0x470 net/netlink/af_netlink.c:2550 netlink_unicast_kernel net/netlink/af_netlink.c:1318 [inline] netlink_unicast+0x82f/0x9e0 net/netlink/af_netlink.c:1344 netlink_sendmsg+0x805/0xb30 net/netlink/af_netlink.c:1894 sock_sendmsg_nosec net/socket.c:727 [inline] __sock_sendmsg+0x21c/0x270 net/socket.c:742 ____sys_sendmsg+0x505/0x820 net/socket.c:2592 ___sys_sendmsg+0x21f/0x2a0 net/socket.c:2646 __sys_sendmsg+0x164/0x220 net/socket.c:2678 do_syscall_32_irqs_on arch/x86/entry/syscall_32.c:83 [inline] __do_fast_syscall_32+0x1dc/0x560 arch/x86/entry/syscall_32.c:307 do_fast_syscall_32+0x34/0x80 arch/x86/entry/syscall_32.c:332 entry_SYSENTER_compat_after_hwframe+0x84/0x8e </TASK> The buggy address belongs to the variable: lacpdu_mcast_addr+0x0/0x40
How severe is CVE-2026-23099?
CVE-2026-23099 has a CVSS 3.x base score of 7.1, rated high severity. It is exploitable over local access with low attack complexity, requires low privileges and no user interaction. Impact on confidentiality is high, integrity none, and availability high.
Is CVE-2026-23099 being actively exploited?
It is not currently listed in CISA's KEV catalog. Its EPSS exploit-prediction score is 0% (5th percentile), an estimate of the probability of exploitation in the next 30 days.
What products are affected by CVE-2026-23099?
CVE-2026-23099 primarily affects Linux Linux Kernel. In total, 7 product configurations (CPEs) are listed as vulnerable; see the affected-products list for the exact versions.
How do I fix CVE-2026-23099?
Review the linked vendor and NVD advisories for patched versions and mitigations, then upgrade or apply the recommended workaround. Given its high severity, prioritise patching exposed systems.
Does CVE-2026-23099 have an EU (EUVD) identifier?
Yes. CVE-2026-23099 is tracked in the ENISA EU Vulnerability Database (EUVD) as EUVD-2026-5443.
When was CVE-2026-23099 published?
CVE-2026-23099 was published on 2026-02-04 and last updated on 2026-06-19.

References

Affected products (7)

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