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CVE-2026-23231
published 2026-03-04

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()…

PriorityP345high7.8CVSS 3.1
AVLACLPRLUINSUCHIHAH
EXPLOIT
EPSS
0.81%
52.4th percentile
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.

Affected

46 ranges· showing 25
VendorProductVersion rangeFixed in
debianlinux< linux 6.18.14-1 (forky)linux 6.18.14-1 (forky)
linuxlinux
linuxlinux>= 91c7b38dc9f0de4f7f444b796d14476bc12df7bc < 2a6586ecfa4ce1413daaafee250d2590e05f1a332a6586ecfa4ce1413daaafee250d2590e05f1a33
linuxlinux>= 91c7b38dc9f0de4f7f444b796d14476bc12df7bc < 7017745068a9068904e1e7a1b170a5785647cc817017745068a9068904e1e7a1b170a5785647cc81
linuxlinux>= 91c7b38dc9f0de4f7f444b796d14476bc12df7bc < f3fe58ce37926a10115ede527d59b91bcc05400af3fe58ce37926a10115ede527d59b91bcc05400a
linuxlinux>= 91c7b38dc9f0de4f7f444b796d14476bc12df7bc < dbd0af8083dd201f07c49110b2ee93710abdff28dbd0af8083dd201f07c49110b2ee93710abdff28
linuxlinux>= 91c7b38dc9f0de4f7f444b796d14476bc12df7bc < 2f9a4ffeb763aec822f8ff3d1e82202d27d46d4b2f9a4ffeb763aec822f8ff3d1e82202d27d46d4b
linuxlinux>= 91c7b38dc9f0de4f7f444b796d14476bc12df7bc < 71e99ee20fc3f662555118cf115944325064753371e99ee20fc3f662555118cf1159443250647533
linuxlinux_kernel>= 0 < 6.18.14-16.18.14-1
linuxlinux_kernel>= 3.16 < 6.1.1656.1.165
linuxlinux_kernel>= 6.13 < 6.18.146.18.14
linuxlinux_kernel>= 6.19 < 6.19.46.19.4
linuxlinux_kernel>= 6.2 < 6.6.1286.6.128
linuxlinux_kernel>= 6.7 < 6.12.756.12.75
msrcazl3_kernel_6.6.126.1-1_on_azure_linux_3.0
msrccbl2_kernel_5.15.200.1-1_on_cbl_mariner_2.0
ubuntulinux
ubuntulinux-aws
ubuntulinux-aws-6.8
ubuntulinux-aws-fips
ubuntulinux-azure
ubuntulinux-azure-6.17
ubuntulinux-azure-6.8
ubuntulinux-azure-fips
ubuntulinux-fips

CVSS provenance

nvdv3.17.8HIGHCVSS:3.1/AV:L/AC:L/PR:L/UI:N/S:U/C:H/I:H/A:H
osv7.8HIGH
vendor_ubuntu9.8CRITICAL
vendor_debian7.8HIGH
vendor_msrc7.8HIGH
vendor_redhat7.8HIGH
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