Use After Free in Linux

CVE-2026-43084

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.

Vulnerability class: Use-After-Free

Published · last modified .

CVSS v3 metric

CVSS v3 base score 7.8 (High). Vector: CVSS:3.1/AV:L/AC:L/PR:L/UI:N/S:U/C:H/I:H/A:H.

EPSS exploit prediction

EPSS: 0.002 (5.7th percentile), scored .

Very low probability of exploitation in the next 30 days; routine patching cadence is appropriate. 6th percentile — 5.7% of CVEs in the catalogue have a lower EPSS than this one. How to read EPSS.

EPSS trend (30 days)EPSS over the last 30 days for CVE-2026-43084: held from 0.001 to 0.002.

EPSS over last 30 days · oldest: 0.001 · newest: 0.002 · change: +0.000

Affected products

  • Linux — versions 371de2bef6582a3f58049b3d18e190924af9c9a0, 870e3e63da8e88daffe9d692a025c711658018a8, 70e2e3ce4f6841e12ec1c104fc76c0e707398ec4
  • Linux Kernel

Weakness classification (CWE)

References

Frequently asked questions

What is CVE-2026-43084?
CVE-2026-43084 is a high-severity vulnerability in Linux, classified under Use After Free. CVSS score: 7.8/10. Published 2026-05-06.
How severe is CVE-2026-43084?
High severity. CVSS v3 base score is 7.8 out of 10.