{"id":"CVE-2026-64576","title":"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()","summary":"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_n…","severity":"high","cvss":7.1,"cvssVector":"CVSS:3.1/AV:L/AC:L/PR:L/UI:N/S:U/C:H/I:N/A:H","published":"2026-08-05","updated":"2026-08-08","source":"NVD","sourceUrl":"https://nvd.nist.gov/vuln/detail/CVE-2026-64576","references":[{"url":"https://git.kernel.org/stable/c/18506d7263768d76ac8e057ba55a4d9da50aad66","label":"416baaa9-dc9f-4396-8d5f-8c081fb06d67"},{"url":"https://git.kernel.org/stable/c/3081702ea5aca0aeed9c1ade8eadf6cde8db6b7d","label":"416baaa9-dc9f-4396-8d5f-8c081fb06d67"},{"url":"https://git.kernel.org/stable/c/6347c5314cee49f364aaf2e40ff15415a57a116e","label":"416baaa9-dc9f-4396-8d5f-8c081fb06d67"},{"url":"https://git.kernel.org/stable/c/c0936c131a71657afc635d0db2ab096d15d473e1","label":"416baaa9-dc9f-4396-8d5f-8c081fb06d67"},{"url":"https://git.kernel.org/stable/c/d536bf205c71f700f6de2086038c3e1d77724715","label":"416baaa9-dc9f-4396-8d5f-8c081fb06d67"},{"url":"https://git.kernel.org/stable/c/eacd2e2117e8682f937967fda1022e7f1c22d91a"},{"url":"https://git.kernel.org/stable/c/37bbd7e1d8df0bec3d187e961783e20c30533d2c"},{"url":"https://security.access.redhat.com/data/csaf/v2/vex/2026/cve-2026-64576.json"},{"url":"https://access.redhat.com/security/cve/CVE-2026-64576"},{"url":"https://bugzilla.redhat.com/show_bug.cgi?id=2511419"},{"url":"https://www.cve.org/CVERecord?id=CVE-2026-64576"},{"url":"https://nvd.nist.gov/vuln/detail/CVE-2026-64576"},{"url":"https://lore.kernel.org/linux-cve-announce/2026080524-CVE-2026-64576-38cf@gregkh/T"}],"tags":["nvd","cve.org","csaf","vex","red-hat"],"epss":0.00121,"epssPercentile":0.01922,"ingestedAt":"2026-08-08T20:29:49.353Z","vendor":"Linux","product":"Linux","affected":["Linux >= 7c37c7e00411b3d1e0c5292368317aca69d1f324 < eacd2e2117e8682f937967fda1022e7f1c22d91a","Linux >= 7c37c7e00411b3d1e0c5292368317aca69d1f324 < 37bbd7e1d8df0bec3d187e961783e20c30533d2c","Linux >= 7c37c7e00411b3d1e0c5292368317aca69d1f324 < c0936c131a71657afc635d0db2ab096d15d473e1","Linux >= 7c37c7e00411b3d1e0c5292368317aca69d1f324 < 3081702ea5aca0aeed9c1ade8eadf6cde8db6b7d","Linux >= 7c37c7e00411b3d1e0c5292368317aca69d1f324 < d536bf205c71f700f6de2086038c3e1d77724715","Linux >= 7c37c7e00411b3d1e0c5292368317aca69d1f324 < 18506d7263768d76ac8e057ba55a4d9da50aad66","Linux >= 7c37c7e00411b3d1e0c5292368317aca69d1f324 < 6347c5314cee49f364aaf2e40ff15415a57a116e","Linux 5.13"],"ssvc":{"exploitation":"none","automatable":"no","technicalImpact":"partial","timestamp":"2026-10-16T15:43:11.555389Z"},"cwe":["CWE-824"],"scores":{"nvd":7.1,"vendor":5.5,"cna":7.1},"slug":"CVE-2026-64576","body":"## Overview\n\nIn 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.\n\n## Remediation\n\nRefer to the linked advisories for vendor-supplied fixes and affected version ranges.\n\n## Vendor advisories\n\n- **Red Hat VEX** · Moderate · affected: Red Hat Enterprise Linux 10, Red Hat Enterprise Linux 9 · no fix planned: Red Hat Enterprise Linux 10, Red Hat Enterprise Linux 9 · updated 2026-10-16 · [vex](https://security.access.redhat.com/data/csaf/v2/vex/2026/cve-2026-64576.json)","depth":"twilight","depthScore":39,"depthScoreParts":{"impact":39.1,"likelihood":0,"exploitation":0,"ransomware":0},"changes":[]}