Linux Kernel Netfilter nfnetlink_queue Entry Leak (CVE-2026-43451)
CVE-2026-43451 Published on May 8, 2026
netfilter: nfnetlink_queue: fix entry leak in bridge verdict error path
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.
Products Associated with CVE-2026-43451
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Affected Versions
Linux:- Version 8d45ff22f1b43249f0cf1baafe0262ca10d1666e and below a907bea273b60d3e604ec4e8e1f6c49954805794 is affected.
- Version 8d45ff22f1b43249f0cf1baafe0262ca10d1666e and below 0b18d1b834ab5a5009be70b530f978d7989e445b is affected.
- Version 8d45ff22f1b43249f0cf1baafe0262ca10d1666e and below b38d2b4603fd3dda24eb8b3dd81c18a0930be97b is affected.
- Version 8d45ff22f1b43249f0cf1baafe0262ca10d1666e and below 47b1c5d1b0944aa88299f55a846fabaefc756982 is affected.
- Version 8d45ff22f1b43249f0cf1baafe0262ca10d1666e and below cf4a4df38d1747e06fc54f9879bd7a6f4178032f is affected.
- Version 8d45ff22f1b43249f0cf1baafe0262ca10d1666e and below 9853d94b82d303fc4ac37d592a23a154096ecd41 is affected.
- Version 8d45ff22f1b43249f0cf1baafe0262ca10d1666e and below 208669df703a25a601f45822b10c413f258bf275 is affected.
- Version 8d45ff22f1b43249f0cf1baafe0262ca10d1666e and below f1ba83755d81c6fc66ac7acd723d238f974091e9 is affected.
- Version 4.7 is affected.
- Before 4.7 is unaffected.
- Version 5.10.253, <= 5.10.* is unaffected.
- Version 5.15.203, <= 5.15.* is unaffected.
- Version 6.1.167, <= 6.1.* is unaffected.
- Version 6.6.130, <= 6.6.* is unaffected.
- Version 6.12.78, <= 6.12.* is unaffected.
- Version 6.18.19, <= 6.18.* is unaffected.
- Version 6.19.9, <= 6.19.* is unaffected.
- Version 7.0, <= * is unaffected.