{"id":"CVE-2026-72421","revision":"ed9fd520dfbb4fcf8a97e95ad31311de","records":[{"revision":"ed9fd520dfbb4fcf8a97e95ad31311de","observedAt":"2026-10-23T15:48:27.903+00:00","statement":{"source":"cve-program","id":"CVE-2026-72421","aliases":[],"title":"ipv4: fib: Don't ignore error route in local/main tables.","description":"In the Linux kernel, the following vulnerability has been resolved:\n\nipv4: fib: Don't ignore error route in local/main tables.\n\nWhen CONFIG_IP_MULTIPLE_TABLES is enabled but no rule is added,\nfib_lookup() performs route lookup directly on two tables.\n\nSince the first lookup does not properly bail out, the result\nof an error route in the merged local/main table could be\noverwritten by another route in the default table:\n\n  # unshare -n\n  # ip link set lo up\n  # ip route add 192.168.0.0/24 dev lo table 253\n  # ip route add unreachable 192.168.0.0/24\n  # ip route get 192.168.0.1\n  192.168.0.1 dev lo table default uid 0\n      cache <local>\n\nOnce a random rule is added, the error route is respected:\n\n  # ip rule add table 0\n  # ip rule del table 0\n  # ip route get 192.168.0.1\n  RTNETLINK answers: No route to host\n\nLet's fix the inconsistent behaviour.","state":0,"publishedAt":"2026-08-15T05:56:40.466+00:00","modifiedAt":"2026-10-16T18:55:23.102+00:00","affected":[{"ecosystem":"Vendor product","name":"Linux","ranges":[],"versions":[],"rawVersionEvidence":"{\n                    \"product\": \"Linux\",\n                    \"vendor\": \"Linux\",\n                    \"defaultStatus\": \"unaffected\",\n                    \"repo\": \"https://git.kernel.org/pub/scm/linux/kernel/git/stable/linux.git\",\n                    \"programFiles\": [\n                        \"include/net/ip_fib.h\"\n                    ],\n                    \"versions\": [\n                        {\n                            \"version\": \"f4530fa574df4d833506c53697ed1daa0d390bf4\",\n                            \"lessThan\": \"a29e95fbc51e8a1b932773fd0e259b2080881443\",\n                            \"status\": \"affected\",\n                            \"versionType\": \"git\"\n                        },\n                        {\n                            \"version\": \"f4530fa574df4d833506c53697ed1daa0d390bf4\",\n                            \"lessThan\": \"5ae18d87a45698e8244d0fcba64c658c35a7dd3d\",\n                            \"status\": \"affected\",\n                            \"versionType\": \"git\"\n                        },\n                        {\n                            \"version\": \"f4530fa574df4d833506c53697ed1daa0d390bf4\",\n                            \"lessThan\": \"9127589aabdee588278e8d0d0bd3709a760a92c8\",\n                            \"status\": \"affected\",\n                            \"versionType\": \"git\"\n                        },\n                        {\n                            \"version\": \"f4530fa574df4d833506c53697ed1daa0d390bf4\",\n                            \"lessThan\": \"49eaf1403201357762d745a35882fb734107d763\",\n                            \"status\": \"affected\",\n                            \"versionType\": \"git\"\n                        },\n                        {\n                            \"version\": \"f4530fa574df4d833506c53697ed1daa0d390bf4\",\n                            \"lessThan\": \"fd25996f57a95d56bc568c89b4921edcf334b7d8\",\n                            \"status\": \"affected\",\n                            \"versionType\": \"git\"\n                        },\n                        {\n                            \"version\": \"f4530fa574df4d833506c53697ed1daa0d390bf4\",\n                            \"lessThan\": \"828fad4fd418bcdb9f5d66fec0d184c52a85ec31\",\n                            \"status\": \"affected\",\n                            \"versionType\": \"git\"\n                        },\n                        {\n                            \"version\": \"f4530fa574df4d833506c53697ed1daa0d390bf4\",\n                            \"lessThan\": \"a668fa160247d7bbe921548cb845f607b8b9305f\",\n                            \"status\": \"affected\",\n                            \"versionType\": \"git\"\n                        },\n                        {\n                            \"version\": \"f4530fa574df4d833506c53697ed1daa0d390bf4\",\n                            \"lessThan\": \"b72f0db64205d9ce462038ba995d5d31eff32dc1\",\n                            \"status\": \"affected\",\n                            \"versionType\": \"git\"\n                        }\n                    ]\n                }"},{"ecosystem":"Vendor product","name":"Linux","ranges":[],"versions":[],"rawVersionEvidence":"{\n                    \"product\": \"Linux\",\n                    \"vendor\": \"Linux\",\n                    \"defaultStatus\": \"affected\",\n                    \"repo\": \"https://git.kernel.org/pub/scm/linux/kernel/git/stable/linux.git\",\n                    \"programFiles\": [\n                        \"include/net/ip_fib.h\"\n                    ],\n                    \"versions\": [\n                        {\n                            \"version\": \"3.6\",\n                            \"status\": \"affected\"\n                        },\n                        {\n                            \"version\": \"0\",\n                            \"lessThan\": \"3.6\",\n                            \"status\": \"unaffected\",\n                            \"versionType\": \"semver\"\n                        },\n                        {\n                            \"version\": \"5.10.261\",\n                            \"lessThanOrEqual\": \"5.10.*\",\n                            \"status\": \"unaffected\",\n                            \"versionType\": \"semver\"\n                        },\n                        {\n                            \"version\": \"5.15.212\",\n                            \"lessThanOrEqual\": \"5.15.*\",\n                            \"status\": \"unaffected\",\n                            \"versionType\": \"semver\"\n                        },\n                        {\n                            \"version\": \"6.1.178\",\n                            \"lessThanOrEqual\": \"6.1.*\",\n                            \"status\": \"unaffected\",\n                            \"versionType\": \"semver\"\n                        },\n                        {\n                            \"version\": \"6.6.145\",\n                            \"lessThanOrEqual\": \"6.6.*\",\n                            \"status\": \"unaffected\",\n                            \"versionType\": \"semver\"\n                        },\n                        {\n                            \"version\": \"6.12.97\",\n                            \"lessThanOrEqual\": \"6.12.*\",\n                            \"status\": \"unaffected\",\n                            \"versionType\": \"semver\"\n                        },\n                        {\n                            \"version\": \"6.18.40\",\n                            \"lessThanOrEqual\": \"6.18.*\",\n                            \"status\": \"unaffected\",\n                            \"versionType\": \"semver\"\n                        },\n                        {\n                            \"version\": \"7.1.5\",\n                            \"lessThanOrEqual\": \"7.1.*\",\n                            \"status\": \"unaffected\",\n                            \"versionType\": \"semver\"\n                        },\n                        {\n                            \"version\": \"7.2\",\n                            \"lessThanOrEqual\": \"*\",\n                            \"status\": \"unaffected\",\n                            \"versionType\": \"original_commit_for_fix\"\n                        }\n                    ]\n                }"}],"metrics":[{"system":"CVSS 3.1","vector":"CVSS:3.1/AV:N/AC:L/PR:N/UI:N/S:C/C:H/I:H/A:N","score":10,"severity":"CRITICAL"}],"references":["https://git.kernel.org/stable/c/a29e95fbc51e8a1b932773fd0e259b2080881443","https://git.kernel.org/stable/c/5ae18d87a45698e8244d0fcba64c658c35a7dd3d","https://git.kernel.org/stable/c/9127589aabdee588278e8d0d0bd3709a760a92c8","https://git.kernel.org/stable/c/49eaf1403201357762d745a35882fb734107d763","https://git.kernel.org/stable/c/fd25996f57a95d56bc568c89b4921edcf334b7d8","https://git.kernel.org/stable/c/828fad4fd418bcdb9f5d66fec0d184c52a85ec31","https://git.kernel.org/stable/c/a668fa160247d7bbe921548cb845f607b8b9305f","https://git.kernel.org/stable/c/b72f0db64205d9ce462038ba995d5d31eff32dc1"],"sourceUrl":"https://www.cve.org/CVERecord?id=CVE-2026-72421","license":"CVE Program Terms of Use","key":"cve-program:CVE-2026-72421","identifiers":["CVE-2026-72421"]},"retained":false,"historicalAffected":[]}],"coverage":[]}