{
    "dataType": "CVE_RECORD",
    "dataVersion": "5.2",
    "cveMetadata": {
        "cveId": "CVE-2026-74562",
        "assignerOrgId": "416baaa9-dc9f-4396-8d5f-8c081fb06d67",
        "state": "PUBLISHED",
        "assignerShortName": "Linux",
        "dateReserved": "2026-08-15T05:44:03.916Z",
        "datePublished": "2026-08-15T12:28:05.154Z",
        "dateUpdated": "2026-08-17T05:48:41.938Z"
    },
    "containers": {
        "cna": {
            "providerMetadata": {
                "orgId": "416baaa9-dc9f-4396-8d5f-8c081fb06d67",
                "shortName": "Linux",
                "dateUpdated": "2026-08-17T05:48:41.938Z"
            },
            "descriptions": [
                {
                    "lang": "en",
                    "value": "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 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."
                }
            ],
            "metrics": [
                {
                    "cvssV3_1": {
                        "version": "3.1",
                        "vectorString": "CVSS:3.1/AV:L/AC:L/PR:L/UI:N/S:C/C:H/I:H/A:H",
                        "baseScore": 8.8,
                        "baseSeverity": "HIGH"
                    },
                    "scenarios": [
                        {
                            "lang": "en",
                            "value": "AV:L - The bug is reached only via local RTNETLINK messages (RTM_NEWNEXTHOP replace and concurrent RTM_NEWROUTE/RTM_DELROUTE) sent on AF_NETLINK sockets, not by processing remote network packets.\nAC:L - An attacker can reliably trigger the race by running concurrent netlink threads that replace a nexthop while deleting IPv6 routes bound to it; both sides of the race are attacker-controlled, as demonstrated by the reported KASAN reproducers.\nPR:L - All vulnerable rtnetlink handlers require CAP_NET_ADMIN via netlink_net_capable(), which unprivileged local users can obtain inside a user/network namespace (unshare -Urn), not only real init-namespace root.\nUI:N - Exploitation requires no victim interaction beyond the attacker issuing coordinated netlink configuration commands from local processes.\nS:C - A successful UAF from CAP_NET_ADMIN inside a user/network namespace can corrupt host kernel memory and escape the container sandbox to compromise the host system.\nC:H - The race performs use-after-free reads of freed fib6_info objects (e.g., fib6_src and fib6_flags in fib6_check_nh_list and rt6_fill_node), enabling arbitrary kernel memory disclosure via heap reuse.\nI:H - Slab UAF on fib6_info during nexthop replace notification can be leveraged with heap spraying for arbitrary kernel writes and local privilege escalation to host root.\nA:H - The bug provably causes slab-use-after-free kernel oops (KASAN) during route notification and can panic or hang the system when triggered repeatedly."
                        }
                    ]
                }
            ],
            "affected": [
                {
                    "product": "Linux",
                    "vendor": "Linux",
                    "defaultStatus": "unaffected",
                    "repo": "https://git.kernel.org/pub/scm/linux/kernel/git/stable/linux.git",
                    "programFiles": [
                        "net/ipv4/nexthop.c"
                    ],
                    "versions": [
                        {
                            "version": "081efd18326e353c6fbfdeff903a83edde953f72",
                            "lessThan": "bb2b072c619c1f741a6234257050f72005dc63ef",
                            "status": "affected",
                            "versionType": "git"
                        },
                        {
                            "version": "081efd18326e353c6fbfdeff903a83edde953f72",
                            "lessThan": "072cd1f21819dedd2252e704d255de3b0cfc61a7",
                            "status": "affected",
                            "versionType": "git"
                        }
                    ]
                },
                {
                    "product": "Linux",
                    "vendor": "Linux",
                    "defaultStatus": "affected",
                    "repo": "https://git.kernel.org/pub/scm/linux/kernel/git/stable/linux.git",
                    "programFiles": [
                        "net/ipv4/nexthop.c"
                    ],
                    "versions": [
                        {
                            "version": "6.16",
                            "status": "affected"
                        },
                        {
                            "version": "0",
                            "lessThan": "6.16",
                            "status": "unaffected",
                            "versionType": "semver"
                        },
                        {
                            "version": "7.1.8",
                            "lessThanOrEqual": "7.1.*",
                            "status": "unaffected",
                            "versionType": "semver"
                        },
                        {
                            "version": "7.2",
                            "lessThanOrEqual": "*",
                            "status": "unaffected",
                            "versionType": "original_commit_for_fix"
                        }
                    ]
                }
            ],
            "cpeApplicability": [
                {
                    "nodes": [
                        {
                            "operator": "OR",
                            "negate": false,
                            "cpeMatch": [
                                {
                                    "vulnerable": true,
                                    "criteria": "cpe:2.3:o:linux:linux_kernel:*:*:*:*:*:*:*:*",
                                    "versionStartIncluding": "6.16",
                                    "versionEndExcluding": "7.1.8"
                                },
                                {
                                    "vulnerable": true,
                                    "criteria": "cpe:2.3:o:linux:linux_kernel:*:*:*:*:*:*:*:*",
                                    "versionStartIncluding": "6.16",
                                    "versionEndExcluding": "7.2"
                                }
                            ]
                        }
                    ]
                }
            ],
            "references": [
                {
                    "url": "https://git.kernel.org/stable/c/bb2b072c619c1f741a6234257050f72005dc63ef"
                },
                {
                    "url": "https://git.kernel.org/stable/c/072cd1f21819dedd2252e704d255de3b0cfc61a7"
                }
            ],
            "title": "nexthop: take nh->lock for f6i_list walks in replace check and notify",
            "x_generator": {
                "engine": "bippy-1.2.0"
            }
        }
    }
}