CVE intelligence and bounded remediation

CVE-2026-43451 — Linux Linux Kernel security vulnerability

Medium CVSS 5.5

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.

Severity
Medium
CVSS
5.5 (3.1)
Published
2026-05-08
CISA KEV
Not currently listed
Ecosystem
linux/kernel
Weaknesses
CWE-401

Affected products

  • linux / linux_kernel
  • linux / linux_kernel / 7.0

Showing 2 representative product identities from 10 source matches. Confirm exact affected versions with the linked vendor and NVD evidence.

Matched remediation archetype

Resource exhaustion and denial of service

This catalog composition supplies bounded fallback guidance. Explicitly reviewed curated workflows load with the complete record below.

Check exposure

  • Identify attacker-influenced work factors including input size, nesting, compression, fan-out, regex cost, allocation, recursion, retries, and connection lifetime.
  • Map per-request and shared CPU, memory, disk, descriptor, thread, queue, and downstream-service limits.
  • Determine whether authentication, tenancy, quotas, and rate controls apply before expensive processing begins.

Remediate safely

  • Bound input size, nesting, expansion, work, concurrency, queue depth, retries, and execution time before resource-intensive processing.
  • Release resources on every success, error, cancellation, and timeout path and use backpressure instead of unbounded buffering.
  • Update affected components and add small deterministic tests that assert resource ceilings rather than exhausting a host.

Authoritative sources

Complete CVE record and remediation plan

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