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Findings

CVE-2026-23231

In the Linux kernel, the following vulnerability has been resolved: netfilter: nf_tables: fix use-after-free in nf_tables_addchain() nf_tables_addchain() publishes the…

Published Mar 4, 2026 · updated Oct 15, 2026 · linux linux kernel

In the Linux kernel, the following vulnerability has been resolved: netfilter: nf_tables: fix use-after-free in nf_tables_addchain() nf_tables_addchain() publishes the chain to table->chains via list_add_tail_rcu() (in nft_chain_add()) before registering hooks. If nf_tables_register_hook() then fails, the error path calls nft_chain_del() (list_del_rcu()) followed by nf_tables_chain_destroy() with no RCU grace period in between. This creates two use-after-free conditions: 1) Control-plane: nf_tables_dump_chains() traverses table->chains under rcu_read_lock(). A concurrent dump can still be walking the chain when the error path frees it. 2) Packet path: for NFPROTO_INET, nf_register_net_hook() briefly installs the IPv4 hook before IPv6 registration fails. Packets entering nft_do_chain() via the transient IPv4 hook can still be dereferencing chain->blob_gen_X when the error path frees the chain. Add synchronize_rcu() between nft_chain_del() and the chain destroy so that all RCU readers -- both dump threads and in-flight packet evaluation -- have finished before the chain is freed.

Code

The project this record applies to. Exploit listings stay in References.

Timeline

Detection, updates, and resolution for this record.

  1. Mar 4, 2026 · NIST NVD

    Detected

    In the Linux kernel, the following vulnerability has been resolved: netfilter: nf_tables: fix use-after-free in nf_tables_addchain() nf_tables_addchain() publishes the chain to table->chains via list_add_tail_rcu() (in nft_chain_add()) before registering hooks. If nf_tables_register_hook() then fails, the error path calls nft_chain_del() (list_del_rcu()) followed by nf_tables_chain_destroy() with

  2. Oct 15, 2026 · NIST NVD

    Updated

    In the Linux kernel, the following vulnerability has been resolved: netfilter: nf_tables: fix use-after-free in nf_tables_addchain() nf_tables_addchain() publishes the chain to table->chains via list_add_tail_rcu() (in nft_chain_add()) before registering hooks. If nf_tables_register_hook() then fails, the error path calls nft_chain_del() (list_del_rcu()) followed by nf_tables_chain_destroy() with

Affected

  • cpe linux/linux kernelversion unspecified

Sources

  • CVE.orgVulnerability recordCVE-2026-23231

    Official CVE identifier

    cve.org
  • FIRST EPSSExploitation probabilityCVE-2026-23231

    30-day exploitation probability 0.8%

    first.org
  • Exploit DatabasePublic exploit reference52549

    Public archive entry. The exploit body is not stored here.

    exploit-db.com
  • NIST NVDVulnerability recordCVE-2026-23231

    In the Linux kernel, the following vulnerability has been resolved: netfilter: nf_tables: fix use-after-free in nf_tables_addchain() nf_tables_addchain() publishes the chain to table->chains via list_add_tail_rcu() (in nft_chain_add()) before registering hooks. If nf_tables_reg

    nvd.nist.gov

References