# CVE-2026-43451: netfilter: nfnetlink_queue: fix entry leak in bridge verdict error path

Status: published. Published: 2026-05-08. Updated: 2026-11-06.

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.

## Remediation

No remediation reported in collected sources

## Affected products and versions

- Linux / Linux: ≥ 8d45ff22f1b43249f0cf1baafe0262ca10d1666e; < a907bea273b60d3e604ec4e8e1f6c49954805794 (affected, git); ≥ 8d45ff22f1b43249f0cf1baafe0262ca10d1666e; < 0b18d1b834ab5a5009be70b530f978d7989e445b (affected, git); ≥ 8d45ff22f1b43249f0cf1baafe0262ca10d1666e; < b38d2b4603fd3dda24eb8b3dd81c18a0930be97b (affected, git); ≥ 8d45ff22f1b43249f0cf1baafe0262ca10d1666e; < 47b1c5d1b0944aa88299f55a846fabaefc756982 (affected, git); ≥ 8d45ff22f1b43249f0cf1baafe0262ca10d1666e; < cf4a4df38d1747e06fc54f9879bd7a6f4178032f (affected, git); ≥ 8d45ff22f1b43249f0cf1baafe0262ca10d1666e; < 9853d94b82d303fc4ac37d592a23a154096ecd41 (affected, git); ≥ 8d45ff22f1b43249f0cf1baafe0262ca10d1666e; < 208669df703a25a601f45822b10c413f258bf275 (affected, git); ≥ 8d45ff22f1b43249f0cf1baafe0262ca10d1666e; < f1ba83755d81c6fc66ac7acd723d238f974091e9 (affected, git). Source: CNA: Linux
- Linux / Linux: 4.7 (affected); ≥ 0; < 4.7 (unaffected, semver); ≥ 5.10.253; ≤ 5.10.* (unaffected, semver); ≥ 5.15.203; ≤ 5.15.* (unaffected, semver); ≥ 6.1.167; ≤ 6.1.* (unaffected, semver); ≥ 6.6.130; ≤ 6.6.* (unaffected, semver); ≥ 6.12.78; ≤ 6.12.* (unaffected, semver); ≥ 6.18.19; ≤ 6.18.* (unaffected, semver); ≥ 6.19.9; ≤ 6.19.* (unaffected, semver); ≥ 7.0; ≤ * (unaffected, original_commit_for_fix). Source: CNA: Linux

## Severity and prioritization

- CISA KEV: No listing in collected sources

- EPSS: 0.12% as of 2026-11-06; percentile 2.04%

- SSVC: exploitation none; automatable no; technical impact partial; source ADP: CISA-ADP

- Weaknesses: Not reported

## Exploit evidence

No exploit evidence in collected sources. This is not proof of no exploitation.

## References

- https://git.kernel.org/stable/c/a907bea273b60d3e604ec4e8e1f6c49954805794 (CNA: Linux)

- https://git.kernel.org/stable/c/0b18d1b834ab5a5009be70b530f978d7989e445b (CNA: Linux)

- https://git.kernel.org/stable/c/b38d2b4603fd3dda24eb8b3dd81c18a0930be97b (CNA: Linux)

- https://git.kernel.org/stable/c/47b1c5d1b0944aa88299f55a846fabaefc756982 (CNA: Linux)

- https://git.kernel.org/stable/c/cf4a4df38d1747e06fc54f9879bd7a6f4178032f (CNA: Linux)

- https://git.kernel.org/stable/c/9853d94b82d303fc4ac37d592a23a154096ecd41 (CNA: Linux)

- https://git.kernel.org/stable/c/208669df703a25a601f45822b10c413f258bf275 (CNA: Linux)

- https://git.kernel.org/stable/c/f1ba83755d81c6fc66ac7acd723d238f974091e9 (CNA: Linux)

## Provenance

- CNA: Linux: https://www.cve.org/CVERecord?id=CVE-2026-43451; retrieved 2026-11-06; source updated 2026-11-06

- FIRST EPSS: https://api.first.org/data/v1/epss?cve=CVE-2026-43451; retrieved 2026-11-06; source updated Not reported

Revision: cd2f9121603df3cbb4347d31b2f0a480e517a858c55b8118c828203978ab6022

Canonical: https://y2.dev/cve/CVE-2026-43451

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