# CVE-2026-23099: bonding: limit BOND_MODE_8023AD to Ethernet devices

> A local attacker can trigger a global out-of-bounds read in the Linux kernel bonding driver, causing a system crash.

- **Severity:** High 7.1 (`CVSS:3.1/AV:L/AC:L/PR:L/UI:N/S:U/C:H/I:N/A:H`)
- **Exploited in the wild:** Not known
- **Login needed:** Any signed-in user
- **Attackable:** Local or same network only
- **Victim action needed:** Not needed
- **Fix available:** Yes
- **Published:** 4 Feb 2026
- **Updated:** 19 Oct 2026
- **Also known as:** AZL-77322, BELL-CVE-2026-23099, DEBIAN-CVE-2026-23099, GHSA-cmv7-4284-j9gc, ROOT-OS-DEBIAN-11-CVE-2026-23099, ROOT-OS-DEBIAN-12-CVE-2026-23099, ROOT-OS-DEBIAN-13-CVE-2026-23099, ROOT-OS-UBUNTU-2204-CVE-2026-23099, ROOT-OS-UBUNTU-2404-CVE-2026-23099, UBUNTU-CVE-2026-23099

## What is CVE-2026-23099?

CVE-2026-23099 is a high-severity memory corruption vulnerability in Linux kernel, published on 4 Feb 2026. It can only be exploited from the same machine or local network, with no action from the victim.

### Official 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

Weakness: CWE-125 (Out-of-bounds Read)

## Which versions are affected by CVE-2026-23099?

It affects 1 product.


Products: Linux kernel.

## How do I fix CVE-2026-23099?

Apply the vendor's patch.

## Is CVE-2026-23099 being exploited?

There is no known exploitation of CVE-2026-23099 in the wild and no public exploit code.

## Other vulnerabilities in Linux kernel

- [CVE-2026-53266](https://insights.sbomify.com/CVE-2026-53266/): Linux Kernel Out-of-Bounds Write (high 8.8, exploited in the wild)
- [CVE-2013-6282](https://insights.sbomify.com/CVE-2013-6282/): Linux Kernel Improper Input Validation (high 8.8, exploited in the wild)
- [CVE-2022-0185](https://insights.sbomify.com/CVE-2022-0185/): Linux Kernel Heap-Based Buffer Overflow (high 8.4, exploited in the wild)
- [CVE-2013-2094](https://insights.sbomify.com/CVE-2013-2094/): Linux Kernel Privilege Escalation (high 8.4, exploited in the wild)
- [CVE-2026-53362](https://insights.sbomify.com/CVE-2026-53362/): Linux Kernel Unspecified (high 7.8, exploited in the wild)

## Fix prompt for AI coding agents

```text
Check this codebase for CVE-2026-23099 and fix it if it is affected.

What it is: CVE-2026-23099 is a high-severity memory corruption vulnerability in Linux kernel, published on 4 Feb 2026. It can only be exploited from the same machine or local network, with no action from the victim.
Exploitation: There is no known exploitation of CVE-2026-23099 in the wild and no public exploit code.

Affected product: Linux kernel. No package-level version data is available, so check the vendor advisory linked from the reference page.

Task:
1. Search the dependency manifests and lockfiles (for example package.json, package-lock.json, requirements.txt, poetry.lock, uv.lock, pom.xml, build.gradle, go.mod, Cargo.lock, Gemfile.lock) and any Dockerfiles for the affected packages, including transitive dependencies.
2. If an affected version is in use, upgrade it to the fixed version for its release line with the project's package manager, so the lockfile is regenerated. Prefer the smallest upgrade that fixes it.
3. If there is no fix, or the upgrade would break the build, do not guess: explain the risk and the safest workaround instead.
4. Run the tests and summarise what changed and why.
5. If nothing in the project is affected, say so and change nothing.

Reference: https://insights.sbomify.com/CVE-2026-23099/ (Markdown: https://insights.sbomify.com/CVE-2026-23099/index.md)
```

## Sources

- CVE record: https://www.cve.org/CVERecord?id=CVE-2026-23099
- NVD: https://nvd.nist.gov/vuln/detail/CVE-2026-23099
- OSV: https://osv.dev/vulnerability/CVE-2026-23099

---
From sbomify Insights: https://insights.sbomify.com/CVE-2026-23099/
Summaries are generated and may contain mistakes; the official description above is the record.
