{"id":"CVE-2026-43374","revision":"624a16c3e9734bf2a1c5e550cd7eea4e","records":[{"revision":"624a16c3e9734bf2a1c5e550cd7eea4e","observedAt":"2026-10-23T15:48:27.903+00:00","statement":{"source":"cve-program","id":"CVE-2026-43374","aliases":[],"title":"net: nexthop: fix percpu use-after-free in remove_nh_grp_entry","description":"In the Linux kernel, the following vulnerability has been resolved:\n\nnet: nexthop: fix percpu use-after-free in remove_nh_grp_entry\n\nWhen removing a nexthop from a group, remove_nh_grp_entry() publishes\nthe new group via rcu_assign_pointer() then immediately frees the\nremoved entry's percpu stats with free_percpu(). However, the\nsynchronize_net() grace period in the caller remove_nexthop_from_groups()\nruns after the free. RCU readers that entered before the publish still\nsee the old group and can dereference the freed stats via\nnh_grp_entry_stats_inc() -> get_cpu_ptr(nhge->stats), causing a\nuse-after-free on percpu memory.\n\nFix by deferring the free_percpu() until after synchronize_net() in the\ncaller. Removed entries are chained via nh_list onto a local deferred\nfree list. After the grace period completes and all RCU readers have\nfinished, the percpu stats are safely freed.","state":0,"publishedAt":"2026-05-08T14:21:24.537+00:00","modifiedAt":"2026-10-19T19:16:28.049+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                        \"net/ipv4/nexthop.c\"\n                    ],\n                    \"versions\": [\n                        {\n                            \"version\": \"f4676ea74b8549cd88dbfe2a592ce4530039e61f\",\n                            \"lessThan\": \"abf4feaee6405f1441929c6ebe7a250f2cd170a7\",\n                            \"status\": \"affected\",\n                            \"versionType\": \"git\"\n                        },\n                        {\n                            \"version\": \"f4676ea74b8549cd88dbfe2a592ce4530039e61f\",\n                            \"lessThan\": \"ab5ebab9664214ba41a7633cb4e72f128204f924\",\n                            \"status\": \"affected\",\n                            \"versionType\": \"git\"\n                        },\n                        {\n                            \"version\": \"f4676ea74b8549cd88dbfe2a592ce4530039e61f\",\n                            \"lessThan\": \"9e08ad731862b22a87cc55f752e16d66cdc9e231\",\n                            \"status\": \"affected\",\n                            \"versionType\": \"git\"\n                        },\n                        {\n                            \"version\": \"f4676ea74b8549cd88dbfe2a592ce4530039e61f\",\n                            \"lessThan\": \"b2662e7593e94ae09b1cf7ee5f09160a3612bcb2\",\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                        \"net/ipv4/nexthop.c\"\n                    ],\n                    \"versions\": [\n                        {\n                            \"version\": \"6.9\",\n                            \"status\": \"affected\"\n                        },\n                        {\n                            \"version\": \"0\",\n                            \"lessThan\": \"6.9\",\n                            \"status\": \"unaffected\",\n                            \"versionType\": \"semver\"\n                        },\n                        {\n                            \"version\": \"6.12.78\",\n                            \"lessThanOrEqual\": \"6.12.*\",\n                            \"status\": \"unaffected\",\n                            \"versionType\": \"semver\"\n                        },\n                        {\n                            \"version\": \"6.18.19\",\n                            \"lessThanOrEqual\": \"6.18.*\",\n                            \"status\": \"unaffected\",\n                            \"versionType\": \"semver\"\n                        },\n                        {\n                            \"version\": \"6.19.9\",\n                            \"lessThanOrEqual\": \"6.19.*\",\n                            \"status\": \"unaffected\",\n                            \"versionType\": \"semver\"\n                        },\n                        {\n                            \"version\": \"7.0\",\n                            \"lessThanOrEqual\": \"*\",\n                            \"status\": \"unaffected\",\n                            \"versionType\": \"original_commit_for_fix\"\n                        }\n                    ]\n                }"}],"metrics":[{"system":"CVSS 3.1","vector":"CVSS:3.1/AV:L/AC:L/PR:L/UI:N/S:U/C:H/I:H/A:H","score":7.8,"severity":"HIGH"}],"references":["https://git.kernel.org/stable/c/abf4feaee6405f1441929c6ebe7a250f2cd170a7","https://git.kernel.org/stable/c/ab5ebab9664214ba41a7633cb4e72f128204f924","https://git.kernel.org/stable/c/9e08ad731862b22a87cc55f752e16d66cdc9e231","https://git.kernel.org/stable/c/b2662e7593e94ae09b1cf7ee5f09160a3612bcb2"],"sourceUrl":"https://www.cve.org/CVERecord?id=CVE-2026-43374","license":"CVE Program Terms of Use","key":"cve-program:CVE-2026-43374","identifiers":["CVE-2026-43374"]},"retained":false,"historicalAffected":[]}],"coverage":[]}