{"id":"CVE-2026-64576","aliases":[],"url":"https://o3.security/vulnerability/CVE-2026-64576","summary":"nexthop: initialize extack in nh_res_bucket_migrate()","details":"In the Linux kernel, the following vulnerability has been resolved:\n\nnexthop: initialize extack in nh_res_bucket_migrate()\n\nnh_res_bucket_migrate() passes an uninitialized netlink_ext_ack to\ncall_nexthop_res_bucket_notifiers(). When\nnh_notifier_res_bucket_info_init() fails (e.g. the kzalloc returns\n-ENOMEM), the error is propagated back before any notifier sets\nextack._msg, and the error path formats the stale pointer with\npr_err_ratelimited(\"%s\\n\", extack._msg). With CONFIG_INIT_STACK_NONE\nthis dereferences uninitialized stack memory:\n\n  Oops: general protection fault, probably for non-canonical address ...\n  KASAN: maybe wild-memory-access in range [...]\n  RIP: 0010:string (lib/vsprintf.c:730)\n   vsnprintf (lib/vsprintf.c:2945)\n   _printk (kernel/printk/printk.c:2504)\n   nh_res_bucket_migrate (net/ipv4/nexthop.c:1816)\n   nh_res_table_upkeep (net/ipv4/nexthop.c:1866)\n   rtm_new_nexthop (net/ipv4/nexthop.c:3323)\n   rtnetlink_rcv_msg (net/core/rtnetlink.c:7076)\n   netlink_sendmsg (net/netlink/af_netlink.c:1900)\n  Kernel panic - not syncing: Fatal exception\n\nZero-initialize extack so _msg is NULL on error paths that never set it.","published":"2026-08-05T08:09:32.529Z","modified":"2026-08-09T03:47:26.184804827Z","cvss":{"score":7.1,"severity":"HIGH","vector":"CVSS:3.1/AV:L/AC:L/PR:L/UI:N/S:U/C:H/I:N/A:H"},"epss":null,"cisaKev":null,"exploitsKnown":0,"affectedPackages":[{"ecosystem":"Linux","name":"Kernel","fixedVersion":"6.6.148"}],"fix":null,"references":[{"type":"WEB","url":"https://git.kernel.org/stable/c/18506d7263768d76ac8e057ba55a4d9da50aad66"},{"type":"WEB","url":"https://git.kernel.org/stable/c/3081702ea5aca0aeed9c1ade8eadf6cde8db6b7d"},{"type":"WEB","url":"https://git.kernel.org/stable/c/6347c5314cee49f364aaf2e40ff15415a57a116e"},{"type":"WEB","url":"https://git.kernel.org/stable/c/c0936c131a71657afc635d0db2ab096d15d473e1"},{"type":"WEB","url":"https://git.kernel.org/stable/c/d536bf205c71f700f6de2086038c3e1d77724715"},{"type":"ADVISORY","url":"https://github.com/CVEProject/cvelistV5/tree/main/cves/2026/64xxx/CVE-2026-64576.json"},{"type":"ADVISORY","url":"https://nvd.nist.gov/vuln/detail/CVE-2026-64576"},{"type":"PACKAGE","url":"https://git.kernel.org/pub/scm/linux/kernel/git/stable/linux.git"}],"provenance":{"sources":["OSV.dev","FIRST.org (EPSS)"],"lastVerified":"2026-08-09T03:47:26.184804827Z"}}