{"id":"CVE-2026-74562","title":"In the Linux kernel, the following vulnerability has been resolved:\n\nnexthop: take nh->lock for f6i_list walks in replace check and notify\n\nfib6_check_nh_list() and __nexthop_replace_notify() walk nh->f6i_list\nduring an RTNL-serialized n…","summary":"In the Linux kernel, the following vulnerability has been resolved:\n\nnexthop: take nh->lock for f6i_list walks in replace check and notify\n\nfib6_check_nh_list() and __nexthop_replace_notify() walk nh->f6i_list\nduring an RTNL-serialized n…","severity":"high","cvss":8.8,"cvssVector":"CVSS:3.1/AV:L/AC:L/PR:L/UI:N/S:C/C:H/I:H/A:H","vendor":"Linux","product":"Linux","affected":["Linux >= 081efd18326e353c6fbfdeff903a83edde953f72 < 4b296d176580a85ccbc7135ebdf66c42087b23a2","Linux >= 081efd18326e353c6fbfdeff903a83edde953f72 < bb2b072c619c1f741a6234257050f72005dc63ef","Linux >= 081efd18326e353c6fbfdeff903a83edde953f72 < 072cd1f21819dedd2252e704d255de3b0cfc61a7","Linux 6.16"],"published":"2026-08-15","updated":"2026-10-15","sourceUpdated":"2026-10-15T11:17:47.710","source":"NVD","sourceUrl":"https://nvd.nist.gov/vuln/detail/CVE-2026-74562","references":[{"url":"https://git.kernel.org/stable/c/072cd1f21819dedd2252e704d255de3b0cfc61a7","label":"416baaa9-dc9f-4396-8d5f-8c081fb06d67"},{"url":"https://git.kernel.org/stable/c/4b296d176580a85ccbc7135ebdf66c42087b23a2","label":"416baaa9-dc9f-4396-8d5f-8c081fb06d67"},{"url":"https://git.kernel.org/stable/c/bb2b072c619c1f741a6234257050f72005dc63ef","label":"416baaa9-dc9f-4396-8d5f-8c081fb06d67"}],"tags":["nvd","cve.org"],"epss":0.00165,"epssPercentile":0.05325,"ingestedAt":"2026-10-15T11:00:41.673Z","slug":"CVE-2026-74562","body":"## Overview\n\nIn the Linux kernel, the following vulnerability has been resolved:\n\nnexthop: take nh->lock for f6i_list walks in replace check and notify\n\nfib6_check_nh_list() and __nexthop_replace_notify() walk nh->f6i_list\nduring an RTNL-serialized nexthop replace without holding nh->lock. IPv6\nRTM_NEWROUTE/RTM_DELROUTE run without RTNL and mutate that list under\nnh->lock (fib6_add_rt2node_nh(), fib6_purge_rt()), so both walks race a\nconcurrent route delete that unlinks and frees a fib6_info:\n\n  BUG: KASAN: slab-use-after-free in rt6_fill_node.isra.0 (net/ipv6/route.c:5799)\n  Read of size 4 at addr ffff888014607e64 by task exploit/143\n   rt6_fill_node.isra.0 (net/ipv6/route.c:5799)\n   fib6_rt_update (net/ipv6/route.c:6412)\n   __nexthop_replace_notify (net/ipv4/nexthop.c:2542)\n   rtm_new_nexthop (net/ipv4/nexthop.c:2554)\n   rtnetlink_rcv_msg (net/core/rtnetlink.c:7076)\n\n  BUG: KASAN: slab-use-after-free in fib6_check_nh_list (net/ipv4/nexthop.c:1605)\n  Read of size 8 at addr ffff888014a7d068 by task exploit/142\n   fib6_check_nh_list (net/ipv4/nexthop.c:1605)\n   rtm_new_nexthop (net/ipv4/nexthop.c:2575)\n   rtnetlink_rcv_msg (net/core/rtnetlink.c:7076)\n\nBoth walks only read the entries and take no tb6_lock, so protect them\nwith nh->lock; fib6_rt_update() uses gfp_any(), which returns GFP_ATOMIC\nunder the lock.\n\n## Remediation\n\nRefer to the linked advisories for vendor-supplied fixes and affected version ranges.","depth":"twilight","depthScore":48,"depthScoreParts":{"impact":48.4,"likelihood":0,"exploitation":0,"ransomware":0},"changes":[]}