CVE-2026-43451

Description

In the Linux kernel, the following vulnerability has been resolved: netfilter: nfnetlink_queue: fix entry leak in bridge verdict error path nfqnl_recv_verdict() calls find_dequeue_entry() to remove the queue entry from the queue data structures, taking ownership of the entry. For PF_BRIDGE packets, it then calls nfqa_parse_bridge() to parse VLAN attributes. If nfqa_parse_bridge() returns an error (e.g. NFQA_VLAN present but NFQA_VLAN_TCI missing), the function returns immediately without freeing the dequeued entry or its sk_buff. This leaks the nf_queue_entry, its associated sk_buff, and all held references (net_device refcounts, struct net refcount). Repeated triggering exhausts kernel memory. Fix this by dropping the entry via nfqnl_reinject() with NF_DROP verdict on the error path, consistent with other error handling in this file.

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EPSS — Exploit Prediction

0.0001

Probability of exploitation

0.02%

Percentile rank

EPSS estimates the probability that this vulnerability will be exploited in the wild within the next 30 days. A higher score means more likely to be exploited.

References

Other References

https://git.kernel.org/stable/c/0b18d1b834ab5a5009be70b530f978d7989e445b https://git.kernel.org/stable/c/208669df703a25a601f45822b10c413f258bf275 https://git.kernel.org/stable/c/47b1c5d1b0944aa88299f55a846fabaefc756982 https://git.kernel.org/stable/c/9853d94b82d303fc4ac37d592a23a154096ecd41 https://git.kernel.org/stable/c/a907bea273b60d3e604ec4e8e1f6c49954805794 https://git.kernel.org/stable/c/b38d2b4603fd3dda24eb8b3dd81c18a0930be97b https://git.kernel.org/stable/c/cf4a4df38d1747e06fc54f9879bd7a6f4178032f https://git.kernel.org/stable/c/f1ba83755d81c6fc66ac7acd723d238f974091e9

Frequently Asked Questions

What is CVE-2026-43451? +

In the Linux kernel, the following vulnerability has been resolved: netfilter: nfnetlink_queue: fix entry leak in bridge verdict error path nfqnl_recv_verdict() calls find_dequeue_entry() to remove the queue entry from the queue data structures, taking ownership of the entry. For PF_BRIDGE packets, it then calls nfqa_parse_bridge() to parse VLAN attributes. If nfqa_parse_bridge() returns an error (e.g. NFQA_VLAN present but NFQA_VLAN_TCI missing), the function returns immediately without freeing the dequeued entry or its sk_buff. This leaks the nf_queue_entry, its associated sk_buff, and all held references (net_device refcounts, struct net refcount). Repeated triggering exhausts kernel memory. Fix this by dropping the entry via nfqnl_reinject() with NF_DROP verdict on the error path, consistent with other error handling in this file.

How do I check if I'm vulnerable to CVE-2026-43451? +

You can use Secably's free Website Scanner to check your website for known vulnerabilities. For infrastructure scanning, use the Port Scanner to identify exposed services that may be affected. Check the vendor advisories linked above for specific patch and version information.