{
    "dataType": "CVE_RECORD",
    "dataVersion": "5.2",
    "cveMetadata": {
        "cveId": "CVE-2026-99201",
        "assignerOrgId": "416baaa9-dc9f-4396-8d5f-8c081fb06d67",
        "state": "PUBLISHED",
        "assignerShortName": "Linux",
        "dateReserved": "2026-09-25T10:25:14.400Z",
        "datePublished": "2026-10-28T10:35:56.069Z",
        "dateUpdated": "2026-10-28T10:35:56.069Z"
    },
    "containers": {
        "cna": {
            "providerMetadata": {
                "orgId": "416baaa9-dc9f-4396-8d5f-8c081fb06d67",
                "shortName": "Linux",
                "dateUpdated": "2026-10-28T10:35:56.069Z"
            },
            "descriptions": [
                {
                    "lang": "en",
                    "value": "In the Linux kernel, the following vulnerability has been resolved:\n\nnetlink: avoid hashing the network namespace pointer\n\nThe netlink rhashtable key includes a raw struct net pointer and a\nuser-controlled port ID. Both /proc/net/netlink and socket diagnostics\nexpose the table's bucket order. By binding and rebinding chosen\nNETLINK_USERSOCK port IDs, an unprivileged reader can distinguish equal\nbuckets and recover the low bits of the Jenkins hash. Its 32-bit seed\nand the limited set of kernel-image slides can then be searched offline\nto recover the address of init_net.\n\nUse the namespace's unique, non-address net_cookie in the comparison\nkey instead. It is assigned before the per-net initializers run and\nremains unchanged for the namespace's lifetime. The lookup key and\nobject hash are still built by netlink_compare_arg_init(), keeping\nlookup, insertion, removal and rehashing consistent while preserving\nnamespace separation. Neither public table walker needs to change.\n\nReading the socket's namespace cookie in netlink_compare() is safe\nunder RCU, including during namespace teardown. netlink_release()\nremoves the socket from the hash table and defers its final put with\ncall_rcu(). cleanup_net() runs the per-net exit methods and waits for\noutstanding RCU callbacks with rcu_barrier() before freeing namespace\nstorage.\n\nUnlike ns.ns_id, net_cookie is also available and initialized during\nsetup_net() in older stable kernels, making the change straightforward\nto backport to v5.15 and later."
                }
            ],
            "affected": [
                {
                    "product": "Linux",
                    "vendor": "Linux",
                    "defaultStatus": "unaffected",
                    "repo": "https://git.kernel.org/pub/scm/linux/kernel/git/stable/linux.git",
                    "programFiles": [
                        "net/netlink/af_netlink.c"
                    ],
                    "versions": [
                        {
                            "version": "c428ecd1a21f1457ca3beb4df71b8a079c410e41",
                            "lessThan": "bdd55b8a8acbf6b4840ab420eb6a63774bf4593b",
                            "status": "affected",
                            "versionType": "git"
                        },
                        {
                            "version": "c428ecd1a21f1457ca3beb4df71b8a079c410e41",
                            "lessThan": "078deff25f8a849ecd1c3fe17b1e473b1cf44f28",
                            "status": "affected",
                            "versionType": "git"
                        },
                        {
                            "version": "c428ecd1a21f1457ca3beb4df71b8a079c410e41",
                            "lessThan": "f88bb3606e4bd11ee035b682cddc2999e604609a",
                            "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/netlink/af_netlink.c"
                    ],
                    "versions": [
                        {
                            "version": "4.1",
                            "status": "affected"
                        },
                        {
                            "version": "0",
                            "lessThan": "4.1",
                            "status": "unaffected",
                            "versionType": "semver"
                        },
                        {
                            "version": "6.18.59",
                            "lessThanOrEqual": "6.18.*",
                            "status": "unaffected",
                            "versionType": "semver"
                        },
                        {
                            "version": "7.2.13",
                            "lessThanOrEqual": "7.2.*",
                            "status": "unaffected",
                            "versionType": "semver"
                        },
                        {
                            "version": "7.3",
                            "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": "4.1",
                                    "versionEndExcluding": "6.18.59"
                                },
                                {
                                    "vulnerable": true,
                                    "criteria": "cpe:2.3:o:linux:linux_kernel:*:*:*:*:*:*:*:*",
                                    "versionStartIncluding": "4.1",
                                    "versionEndExcluding": "7.2.13"
                                },
                                {
                                    "vulnerable": true,
                                    "criteria": "cpe:2.3:o:linux:linux_kernel:*:*:*:*:*:*:*:*",
                                    "versionStartIncluding": "4.1",
                                    "versionEndExcluding": "7.3"
                                }
                            ]
                        }
                    ]
                }
            ],
            "references": [
                {
                    "url": "https://git.kernel.org/stable/c/bdd55b8a8acbf6b4840ab420eb6a63774bf4593b"
                },
                {
                    "url": "https://git.kernel.org/stable/c/078deff25f8a849ecd1c3fe17b1e473b1cf44f28"
                },
                {
                    "url": "https://git.kernel.org/stable/c/f88bb3606e4bd11ee035b682cddc2999e604609a"
                }
            ],
            "title": "netlink: avoid hashing the network namespace pointer",
            "x_generator": {
                "engine": "bippy-1.2.0"
            }
        }
    }
}