{"id":"CVE-2026-23381","summary":"net: bridge: fix nd_tbl NULL dereference when IPv6 is disabled","details":"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() 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-\u003end_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  \u003cIRQ\u003e\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.","modified":"2026-04-18T18:44:07.745743440Z","published":"2026-03-25T10:28:00.416Z","related":["SUSE-SU-2026:21114-1","SUSE-SU-2026:21123-1"],"database_specific":{"cna_assigner":"Linux","osv_generated_from":"https://github.com/CVEProject/cvelistV5/tree/main/cves/2026/23xxx/CVE-2026-23381.json"},"references":[{"type":"PACKAGE","url":"https://git.kernel.org/pub/scm/linux/kernel/git/stable/linux.git"},{"type":"WEB","url":"https://git.kernel.org/stable/c/20ef5c25422f97dd09d751e5ae6c18406cdc78e6"},{"type":"WEB","url":"https://git.kernel.org/stable/c/33dec6f10777d5a8f71c0a200f690da5ae3c2e55"},{"type":"WEB","url":"https://git.kernel.org/stable/c/7a894eb5de246d79f13105c55a67381039a24d44"},{"type":"WEB","url":"https://git.kernel.org/stable/c/a12cdaa3375f0bd3c8f4e564be7c143529abfe5b"},{"type":"WEB","url":"https://git.kernel.org/stable/c/aa73deb3b6b730ec280d45b3f423bfa9e17bc122"},{"type":"WEB","url":"https://git.kernel.org/stable/c/e5e890630533bdc15b26a34bb8e7ef539bdf1322"},{"type":"ADVISORY","url":"https://github.com/CVEProject/cvelistV5/tree/main/cves/2026/23xxx/CVE-2026-23381.json"},{"type":"ADVISORY","url":"https://nvd.nist.gov/vuln/detail/CVE-2026-23381"}],"affected":[{"ranges":[{"type":"GIT","repo":"https://git.kernel.org/pub/scm/linux/kernel/git/stable/linux.git","events":[{"introduced":"ed842faeb2bd49256f00485402f3113205f91d30"},{"fixed":"7a894eb5de246d79f13105c55a67381039a24d44"},{"fixed":"a12cdaa3375f0bd3c8f4e564be7c143529abfe5b"},{"fixed":"aa73deb3b6b730ec280d45b3f423bfa9e17bc122"},{"fixed":"33dec6f10777d5a8f71c0a200f690da5ae3c2e55"},{"fixed":"20ef5c25422f97dd09d751e5ae6c18406cdc78e6"},{"fixed":"e5e890630533bdc15b26a34bb8e7ef539bdf1322"}]}],"database_specific":{"source":"https://storage.googleapis.com/osv-test-cve-osv-conversion/osv-output/CVE-2026-23381.json"}},{"package":{"name":"Kernel","ecosystem":"Linux"},"ranges":[{"type":"ECOSYSTEM","events":[{"introduced":"4.15.0"},{"fixed":"6.1.167"}]},{"type":"ECOSYSTEM","events":[{"introduced":"6.2.0"},{"fixed":"6.6.130"}]},{"type":"ECOSYSTEM","events":[{"introduced":"6.7.0"},{"fixed":"6.12.77"}]},{"type":"ECOSYSTEM","events":[{"introduced":"6.13.0"},{"fixed":"6.18.17"}]},{"type":"ECOSYSTEM","events":[{"introduced":"6.19.0"},{"fixed":"6.19.7"}]}],"database_specific":{"source":"https://storage.googleapis.com/osv-test-cve-osv-conversion/osv-output/CVE-2026-23381.json"}}],"schema_version":"1.7.5"}