{"apiVersion":"1.0","identifier":"CVE-2026-74561","description":"In the Linux kernel, the following vulnerability has been resolved: nexthop: avoid unlocked f6i_list walk in nh_rt_cache_flush nh_rt_cache_flush() walks nh->f6i_list during an RTNL-serialized nexthop replace without holding nh->lock, racing the unlocked IPv6 route add/delete that mutate the list under nh->lock and free fib6_info entries (nh_rt_cache_flush() is inlined into rtm_new_nexthop()): BUG: KASAN: slab-use-after-free in nh_rt_cache_flush (net/ipv4/nexthop.c:2243) Read of size 8 at addr ffff888012953e18 by task exploit/146 nh_rt_cache_flush (net/ipv4/nexthop.c:2243) replace_nexthop (net/ipv4/nexthop.c:2610) rtm_new_nexthop (net/ipv4/nexthop.c:3323) rtnetlink_rcv_msg (net/core/rtnetlink.c:7076) Unlike the other f6i_list walks, this one bumps each route-s sernum via fib6_update_sernum_upto_root(), which needs tb6_lock; taking nh->lock around it would invert the established tb6_lock -> nh->lock order and deadlock. As the only purpose is to invalidate cached dsts, bump the IPv6 sernum for the whole netns with rt_genid_bump_ipv6() instead, mirroring the rt_cache_flush() already done for IPv4 just above.","publishedAt":"2026-08-15T13:18:01","lastModifiedAt":"2026-08-17T06:19:54","sourceUrl":"https://nvd.nist.gov/vuln/detail/CVE-2026-74561","cvssScore":8.8,"cvssVector":"CVSS:3.1/AV:L/AC:L/PR:L/UI:N/S:C/C:H/I:H/A:H","epssProbability":0.00112,"riskScore":0.89,"affectedProduct":"Linux kernel","affectedVersions":"unknown","vulnerabilityType":"Kernel","operatingSystems":[],"links":{"self":"https://www.redsauce.net/api/cves/CVE-2026-74561","webPages":{"es":"https://www.redsauce.net/es/cves/CVE-2026-74561","en":"https://www.redsauce.net/en/cves/CVE-2026-74561","fr":"https://www.redsauce.net/fr/cves/CVE-2026-74561","pt":"https://www.redsauce.net/pt/cves/CVE-2026-74561","de":"https://www.redsauce.net/de/cves/CVE-2026-74561","sk":"https://www.redsauce.net/sk/cves/CVE-2026-74561","el":"https://www.redsauce.net/el/cves/CVE-2026-74561"},"source":"https://nvd.nist.gov/vuln/detail/CVE-2026-74561"}}