CVE-2026-23231netfilter: nf_tables: fix use-after-free in nf_tables_addchain()
Updated under an hour ago ()
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No exploitation reported and no EPSS estimate yet.
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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.
- CVSS
- 7.8 HIGH (v3.1, CNA)CVSS:3.1/AV:L/AC:L/PR:L/UI:N/S:U/C:H/I:H/A:H
- Weakness (CWE)
- Not given
- Known exploited
- Not in CISA's KEV catalog
- EPSS (exploitation in the next 30 days)
- Not loaded for this CVE
- Assigned by
- Linux
- NVD analysis
- Modified
- Record last updated
- Oct 15, 2026
- First seen by InfoSec Signals
- Oct 9, 2026
Affected products
Linux Linux linux:linux (from the name) | 91c7b38dc9f0de4f7f444b796d14476bc12df7bc builds before 2a6586ecfa4ce1413daaafee250d2590e05f1a33; from 91c7b38dc9f0de4f7f444b796d14476bc12df7bc before 7017745068a9068904e1e7a1b170a5785647cc81; from 91c7b38dc9f0de4f7f444b796d14476bc12df7bc before f3fe58ce37926a10115ede527d59b91bcc05400a; from 91c7b38dc9f0de4f7f444b796d14476bc12df7bc before dbd0af8083dd201f07c49110b2ee93710abdff28; 91c7b38dc9f0de4f7f444b796d14476bc12df7bc builds before 2f9a4ffeb763aec822f8ff3d1e82202d27d46d4b; 91c7b38dc9f0de4f7f444b796d14476bc12df7bc builds before 71e99ee20fc3f662555118cf1159443250647533 | CNA record |
Siemens RUGGEDCOM RST2428P siemens:ruggedcom_rst2428p (from the name) | before V4.0 | CISA ADP |
Siemens SIMATIC S7-1500 CPU 1518-4 PN/DP MFP siemens:simatic_s7_1500_cpu_1518_4_pn_dp_mfp (from the name) | from V3.1.6 | CISA ADP |
Siemens SIMATIC S7-1500 CPU 1518F-4 PN/DP MFP siemens:simatic_s7_1500_cpu_1518f_4_pn_dp_mfp (from the name) | from V3.1.6 | CISA ADP |
Siemens SIMATIC S7-1500 TM MFP - GNU/Linux subsystem siemens:simatic_s7_1500_tm_mfp_gnu_linux_subsystem (from the name) | all versions | CISA ADP |
Siemens SIPLUS S7-1500 CPU 1518-4 PN/DP MFP siemens:siplus_s7_1500_cpu_1518_4_pn_dp_mfp (from the name) | from V3.1.6 | CISA ADP |
linux linux_kernel linux:linux_kernel | from 3.16 before 6.1.165; from 6.2 before 6.6.128; from 6.7 before 6.12.75; from 6.13 before 6.18.14; from 6.19 before 6.19.4 | NVD |
References
- https://git.kernel.org/stable/c/2a6586ecfa4ce1413daaafee250d2590e05f1a33patch
- https://git.kernel.org/stable/c/7017745068a9068904e1e7a1b170a5785647cc81patch
- https://git.kernel.org/stable/c/f3fe58ce37926a10115ede527d59b91bcc05400apatch
- https://git.kernel.org/stable/c/dbd0af8083dd201f07c49110b2ee93710abdff28patch
- https://git.kernel.org/stable/c/2f9a4ffeb763aec822f8ff3d1e82202d27d46d4bpatch
- https://git.kernel.org/stable/c/71e99ee20fc3f662555118cf1159443250647533patch
- https://cert-portal.siemens.com/productcert/html/ssa-019113.html
- https://cert-portal.siemens.com/productcert/html/ssa-082556.html
- https://cert-portal.siemens.com/productcert/html/ssa-253495.html
- https://cert-portal.siemens.com/productcert/html/ssa-457936.html
- https://cert-portal.siemens.com/productcert/html/ssa-784472.html
The CVE record on cve.org NVD's entry
The CVE record is authoritative. Products marked “from the name” were identified from the CNA's free-text names, not a CPE, and are matched less certainly. This product uses the NVD API but is not endorsed or certified by the NVD.