{"id":"CVE-2026-31424","title":"In the Linux kernel, the following vulnerability has been resolved:\n\nnetfilter: x_tables: restrict xt_check_match/xt_check_target extensions for NFPROTO_ARP\n\nWeiming Shi says:\n\nxt_match and xt_target structs registered with NFPROTO_UNSPE…","summary":"In the Linux kernel, the following vulnerability has been resolved:\n\nnetfilter: x_tables: restrict xt_check_match/xt_check_target extensions for NFPROTO_ARP\n\nWeiming Shi says:\n\nxt_match and xt_target structs registered with NFPROTO_UNSPE…","severity":"medium","cvss":5.5,"cvssVector":"CVSS:3.1/AV:L/AC:L/PR:L/UI:N/S:U/C:N/I:N/A:H","cwe":["CWE-476"],"vendor":"linux","product":"linux_kernel","affected":["linux_kernel >= 2.6.39, < 5.10.253","linux_kernel >= 5.11, < 5.15.203","linux_kernel >= 5.16, < 6.1.168","linux_kernel >= 6.2, < 6.6.134","linux_kernel >= 6.7, < 6.12.81","linux_kernel >= 6.13, < 6.18.22","linux_kernel >= 6.19, < 6.19.12","linux_kernel = 7.0"],"patched":["linux_kernel 6.19.12"],"published":"2026-04-13","updated":"2026-10-15","sourceUpdated":"2026-10-15T02:19:04.383","source":"NVD","sourceUrl":"https://nvd.nist.gov/vuln/detail/CVE-2026-31424","references":[{"url":"https://git.kernel.org/stable/c/1cd6313c8644bfebbd813a05da9daa21b09dd68c","label":"416baaa9-dc9f-4396-8d5f-8c081fb06d67"},{"url":"https://git.kernel.org/stable/c/3d5d488f11776738deab9da336038add95d342d1","label":"416baaa9-dc9f-4396-8d5f-8c081fb06d67"},{"url":"https://git.kernel.org/stable/c/3e79374b03bf9a2f282f0eb1d0ac3776f7e0f28a","label":"416baaa9-dc9f-4396-8d5f-8c081fb06d67"},{"url":"https://git.kernel.org/stable/c/80e3c75f71c3ea1e62fcb032382de13e00a68f8b","label":"416baaa9-dc9f-4396-8d5f-8c081fb06d67"},{"url":"https://git.kernel.org/stable/c/d9a0af9e43416aa50c0595e15fa01365a1c72c49","label":"416baaa9-dc9f-4396-8d5f-8c081fb06d67"},{"url":"https://git.kernel.org/stable/c/dc3e27dd7d76e21106b8f9bbdc31f5da74a89014","label":"416baaa9-dc9f-4396-8d5f-8c081fb06d67"},{"url":"https://git.kernel.org/stable/c/e7e1b6bcb389c8708003d40613a59ff2496f6b1f","label":"416baaa9-dc9f-4396-8d5f-8c081fb06d67"},{"url":"https://git.kernel.org/stable/c/f00ac65c90ea475719e08d629e2e26c8b4e6999b","label":"416baaa9-dc9f-4396-8d5f-8c081fb06d67"},{"url":"https://cert-portal.siemens.com/productcert/html/ssa-019113.html","label":"0b142b55-0307-4c5a-b3c9-f314f3fb7c5e"},{"url":"https://cert-portal.siemens.com/productcert/html/ssa-082556.html","label":"0b142b55-0307-4c5a-b3c9-f314f3fb7c5e"},{"url":"https://cert-portal.siemens.com/productcert/html/ssa-457936.html","label":"0b142b55-0307-4c5a-b3c9-f314f3fb7c5e"}],"tags":["nvd","cve.org"],"epss":0.00122,"epssPercentile":0.01989,"ingestedAt":"2026-09-08T15:33:26.990Z","slug":"CVE-2026-31424","body":"## Overview\n\nIn the Linux kernel, the following vulnerability has been resolved:\n\nnetfilter: x_tables: restrict xt_check_match/xt_check_target extensions for NFPROTO_ARP\n\nWeiming Shi says:\n\nxt_match and xt_target structs registered with NFPROTO_UNSPEC can be\nloaded by any protocol family through nft_compat. When such a\nmatch/target sets .hooks to restrict which hooks it may run on, the\nbitmask uses NF_INET_* constants. This is only correct for families\nwhose hook layout matches NF_INET_*: IPv4, IPv6, INET, and bridge\nall share the same five hooks (PRE_ROUTING ... POST_ROUTING).\n\nARP only has three hooks (IN=0, OUT=1, FORWARD=2) with different\nsemantics. Because NF_ARP_OUT == 1 == NF_INET_LOCAL_IN, the .hooks\nvalidation silently passes for the wrong reasons, allowing matches to\nrun on ARP chains where the hook assumptions (e.g. state->in being\nset on input hooks) do not hold. This leads to NULL pointer\ndereferences; xt_devgroup is one concrete example:\n\n Oops: general protection fault, probably for non-canonical address 0xdffffc0000000044: 0000 [#1] SMP KASAN NOPTI\n KASAN: null-ptr-deref in range [0x0000000000000220-0x0000000000000227]\n RIP: 0010:devgroup_mt+0xff/0x350\n Call Trace:\n  <TASK>\n  nft_match_eval (net/netfilter/nft_compat.c:407)\n  nft_do_chain (net/netfilter/nf_tables_core.c:285)\n  nft_do_chain_arp (net/netfilter/nft_chain_filter.c:61)\n  nf_hook_slow (net/netfilter/core.c:623)\n  arp_xmit (net/ipv4/arp.c:666)\n  </TASK>\n Kernel panic - not syncing: Fatal exception in interrupt\n\nFix it by restricting arptables to NFPROTO_ARP extensions only.\nNote that arptables-legacy only supports:\n\n- arpt_CLASSIFY\n- arpt_mangle\n- arpt_MARK\n\nthat provide explicit NFPROTO_ARP match/target declarations.\n\n## Affected\n\n- `linux_kernel >= 2.6.39, < 5.10.253`\n- `linux_kernel >= 5.11, < 5.15.203`\n- `linux_kernel >= 5.16, < 6.1.168`\n- `linux_kernel >= 6.2, < 6.6.134`\n- `linux_kernel >= 6.7, < 6.12.81`\n- `linux_kernel >= 6.13, < 6.18.22`\n- `linux_kernel >= 6.19, < 6.19.12`\n- `linux_kernel = 7.0`\n\n## Remediation\n\nUpgrade past the affected range:\n\n- `linux_kernel 6.19.12`","depth":"sunlit","depthScore":30,"depthScoreParts":{"impact":30.3,"likelihood":0,"exploitation":0,"ransomware":0},"changes":[{"seq":221703,"id":"CVE-2026-31424","ts":1792035330185,"field":"cvss","old":null,"new":"5.5"},{"seq":221702,"id":"CVE-2026-31424","ts":1792035330185,"field":"severity","old":"none","new":"medium"}]}