{"cve":"CVE-2026-31424","nvd":{"published":"2026-04-13T14:16:12.240","modified":"2026-10-15T02:19:04.383","status":"Modified","description":"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_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.","cvss_v4":null,"cvss_v3":{"version":"3.1","vector":"CVSS:3.1/AV:L/AC:L/PR:L/UI:N/S:U/C:N/I:N/A:H","score":5.5},"cwes":["CWE-476"],"references":["https://git.kernel.org/stable/c/1cd6313c8644bfebbd813a05da9daa21b09dd68c","https://git.kernel.org/stable/c/3d5d488f11776738deab9da336038add95d342d1","https://git.kernel.org/stable/c/3e79374b03bf9a2f282f0eb1d0ac3776f7e0f28a","https://git.kernel.org/stable/c/80e3c75f71c3ea1e62fcb032382de13e00a68f8b","https://git.kernel.org/stable/c/d9a0af9e43416aa50c0595e15fa01365a1c72c49"],"products":["linux:linux_kernel"],"source":"nvd","synced_at":"2026-10-19T22:30:49.762551342+00:00"},"epss":{"cve":"CVE-2026-31424","score":0.00122,"percentile":0.01988,"date":"2026-10-25"},"kev":null,"osv":[],"attribution":["This product uses the NVD API but is not endorsed or certified by the NVD.","EPSS scores: FIRST Exploit Prediction Scoring System, https://www.first.org/epss","Known exploited vulnerabilities: CISA Known Exploited Vulnerabilities Catalog, https://www.cisa.gov/known-exploited-vulnerabilities-catalog","Package advisories: OSV (https://osv.dev), from the GitHub Advisory Database, PyPA, Go, RustSec and other ecosystem databases, under CC-BY 4.0 or CC0","CVE records: the CVE Program's CVE List (https://www.cve.org), under its terms of use (https://www.cve.org/Legal/TermsOfUse). CVE is a registered trademark of The MITRE Corporation; this product is not affiliated with the CVE Program."]}