{"id":"CVE-2026-23381","title":"net: bridge: fix nd_tbl NULL dereference when IPv6 is disabled","summary":"In the Linux kernel, the following vulnerability has been resolved:\n\nnet: bridge: fix nd_tbl NULL dereference when IPv6 is disabled\n\nWhen booting with the 'ipv6.disable=1' parameter, the nd_tbl is never\ninitialized because inet6_init() e…","severity":"none","vendor":"Linux","product":"Linux","affected":["Linux >= ed842faeb2bd49256f00485402f3113205f91d30 < a9d712ccfeef737c0e700a4b5b98f310e07b6b60","Linux >= ed842faeb2bd49256f00485402f3113205f91d30 < a5c56e65b685360dd3f2278aeff8c21061feb665","Linux >= ed842faeb2bd49256f00485402f3113205f91d30 < 7a894eb5de246d79f13105c55a67381039a24d44","Linux >= ed842faeb2bd49256f00485402f3113205f91d30 < a12cdaa3375f0bd3c8f4e564be7c143529abfe5b","Linux >= ed842faeb2bd49256f00485402f3113205f91d30 < aa73deb3b6b730ec280d45b3f423bfa9e17bc122","Linux >= ed842faeb2bd49256f00485402f3113205f91d30 < 33dec6f10777d5a8f71c0a200f690da5ae3c2e55","Linux >= ed842faeb2bd49256f00485402f3113205f91d30 < 20ef5c25422f97dd09d751e5ae6c18406cdc78e6","Linux >= ed842faeb2bd49256f00485402f3113205f91d30 < e5e890630533bdc15b26a34bb8e7ef539bdf1322","Linux 4.15"],"published":"2026-03-25","updated":"2026-09-08","sourceUpdated":"2026-09-08T08:45:53.238Z","source":"CVEORG","sourceUrl":"https://www.cve.org/CVERecord?id=CVE-2026-23381","references":[{"url":"https://git.kernel.org/stable/c/a9d712ccfeef737c0e700a4b5b98f310e07b6b60"},{"url":"https://git.kernel.org/stable/c/a5c56e65b685360dd3f2278aeff8c21061feb665"},{"url":"https://git.kernel.org/stable/c/7a894eb5de246d79f13105c55a67381039a24d44"},{"url":"https://git.kernel.org/stable/c/a12cdaa3375f0bd3c8f4e564be7c143529abfe5b"},{"url":"https://git.kernel.org/stable/c/aa73deb3b6b730ec280d45b3f423bfa9e17bc122"},{"url":"https://git.kernel.org/stable/c/33dec6f10777d5a8f71c0a200f690da5ae3c2e55"},{"url":"https://git.kernel.org/stable/c/20ef5c25422f97dd09d751e5ae6c18406cdc78e6"},{"url":"https://git.kernel.org/stable/c/e5e890630533bdc15b26a34bb8e7ef539bdf1322"}],"tags":["cve.org"],"epss":0.0012,"epssPercentile":0.0208,"ingestedAt":"2026-09-08T15:33:26.992Z","slug":"CVE-2026-23381","body":"## Overview\n\nIn the Linux kernel, the following vulnerability has been resolved:\n\nnet: bridge: fix nd_tbl NULL dereference when IPv6 is disabled\n\nWhen booting with the 'ipv6.disable=1' parameter, the nd_tbl is never\ninitialized because inet6_init() exits before ndisc_init() is called\nwhich initializes it. Then, if neigh_suppress is enabled and an ICMPv6\nNeighbor Discovery packet reaches the bridge, br_do_suppress_nd() will\ndereference ipv6_stub->nd_tbl which is NULL, passing it to\nneigh_lookup(). This causes a kernel NULL pointer dereference.\n\n BUG: kernel NULL pointer dereference, address: 0000000000000268\n Oops: 0000 [#1] PREEMPT SMP NOPTI\n [...]\n RIP: 0010:neigh_lookup+0x16/0xe0\n [...]\n Call Trace:\n  <IRQ>\n  ? neigh_lookup+0x16/0xe0\n  br_do_suppress_nd+0x160/0x290 [bridge]\n  br_handle_frame_finish+0x500/0x620 [bridge]\n  br_handle_frame+0x353/0x440 [bridge]\n  __netif_receive_skb_core.constprop.0+0x298/0x1110\n  __netif_receive_skb_one_core+0x3d/0xa0\n  process_backlog+0xa0/0x140\n  __napi_poll+0x2c/0x170\n  net_rx_action+0x2c4/0x3a0\n  handle_softirqs+0xd0/0x270\n  do_softirq+0x3f/0x60\n\nFix this by replacing IS_ENABLED(IPV6) call with ipv6_mod_enabled() in\nthe callers. This is in essence disabling NS/NA suppression when IPv6 is\ndisabled.\n\n## Affected\n\n- `Linux >= ed842faeb2bd49256f00485402f3113205f91d30 < a9d712ccfeef737c0e700a4b5b98f310e07b6b60`\n- `Linux >= ed842faeb2bd49256f00485402f3113205f91d30 < a5c56e65b685360dd3f2278aeff8c21061feb665`\n- `Linux >= ed842faeb2bd49256f00485402f3113205f91d30 < 7a894eb5de246d79f13105c55a67381039a24d44`\n- `Linux >= ed842faeb2bd49256f00485402f3113205f91d30 < a12cdaa3375f0bd3c8f4e564be7c143529abfe5b`\n- `Linux >= ed842faeb2bd49256f00485402f3113205f91d30 < aa73deb3b6b730ec280d45b3f423bfa9e17bc122`\n- `Linux >= ed842faeb2bd49256f00485402f3113205f91d30 < 33dec6f10777d5a8f71c0a200f690da5ae3c2e55`\n- `Linux >= ed842faeb2bd49256f00485402f3113205f91d30 < 20ef5c25422f97dd09d751e5ae6c18406cdc78e6`\n- `Linux >= ed842faeb2bd49256f00485402f3113205f91d30 < e5e890630533bdc15b26a34bb8e7ef539bdf1322`\n- `Linux 4.15`\n\n## Remediation\n\nRefer to the linked advisories for vendor-supplied fixes and affected version ranges.","depth":"sunlit","depthScore":3,"depthScoreParts":{"impact":2.8,"likelihood":0,"exploitation":0,"ransomware":0},"changes":[]}