CVE-2026-43374

{"id": "CVE-2026-43374", "cveTags": [], "metrics": {"ssvcV203": [{"source": "134c704f-9b21-4f2e-91b3-4a467353bcc0", "ssvcData": {"id": "CVE-2026-43374", "role": "CISA Coordinator", "options": [{"exploitation": "none"}, {"automatable": "no"}, {"technicalImpact": "total"}], "version": "2.0.3", "timestamp": "2026-10-16T15:16:55.959084Z"}}], "cvssMetricV31": [{"type": "Secondary", "source": "416baaa9-dc9f-4396-8d5f-8c081fb06d67", "cvssData": {"scope": "UNCHANGED", "version": "3.1", "baseScore": 7.8, "attackVector": "LOCAL", "baseSeverity": "HIGH", "vectorString": "CVSS:3.1/AV:L/AC:L/PR:L/UI:N/S:U/C:H/I:H/A:H", "integrityImpact": "HIGH", "userInteraction": "NONE", "attackComplexity": "LOW", "availabilityImpact": "HIGH", "privilegesRequired": "LOW", "confidentialityImpact": "HIGH"}, "impactScore": 5.9, "exploitabilityScore": 1.8}]}, "affected": [{"source": "416baaa9-dc9f-4396-8d5f-8c081fb06d67", "affectedData": [{"repo": "https://git.kernel.org/pub/scm/linux/kernel/git/stable/linux.git", "vendor": "Linux", "product": "Linux", "versions": [{"status": "affected", "version": "f4676ea74b8549cd88dbfe2a592ce4530039e61f", "lessThan": "abf4feaee6405f1441929c6ebe7a250f2cd170a7", "versionType": "git"}, {"status": "affected", "version": "f4676ea74b8549cd88dbfe2a592ce4530039e61f", "lessThan": "ab5ebab9664214ba41a7633cb4e72f128204f924", "versionType": "git"}, {"status": "affected", "version": "f4676ea74b8549cd88dbfe2a592ce4530039e61f", "lessThan": "9e08ad731862b22a87cc55f752e16d66cdc9e231", "versionType": "git"}, {"status": "affected", "version": "f4676ea74b8549cd88dbfe2a592ce4530039e61f", "lessThan": "b2662e7593e94ae09b1cf7ee5f09160a3612bcb2", "versionType": "git"}], "programFiles": ["net/ipv4/nexthop.c"], "defaultStatus": "unaffected"}, {"repo": "https://git.kernel.org/pub/scm/linux/kernel/git/stable/linux.git", "vendor": "Linux", "product": "Linux", "versions": [{"status": "affected", "version": "6.9"}, {"status": "unaffected", "version": "0", "lessThan": "6.9", "versionType": "semver"}, {"status": "unaffected", "version": "6.12.78", "versionType": "semver", "lessThanOrEqual": "6.12.*"}, {"status": "unaffected", "version": "6.18.19", "versionType": "semver", "lessThanOrEqual": "6.18.*"}, {"status": "unaffected", "version": "6.19.9", "versionType": "semver", "lessThanOrEqual": "6.19.*"}, {"status": "unaffected", "version": "7.0", "versionType": "original_commit_for_fix", "lessThanOrEqual": "*"}], "programFiles": ["net/ipv4/nexthop.c"], "defaultStatus": "affected"}]}], "published": "2026-05-08T15:16:48.547", "references": [{"url": "https://git.kernel.org/stable/c/9e08ad731862b22a87cc55f752e16d66cdc9e231", "tags": ["Patch"], "source": "416baaa9-dc9f-4396-8d5f-8c081fb06d67"}, {"url": "https://git.kernel.org/stable/c/ab5ebab9664214ba41a7633cb4e72f128204f924", "tags": ["Patch"], "source": "416baaa9-dc9f-4396-8d5f-8c081fb06d67"}, {"url": "https://git.kernel.org/stable/c/abf4feaee6405f1441929c6ebe7a250f2cd170a7", "tags": ["Patch"], "source": "416baaa9-dc9f-4396-8d5f-8c081fb06d67"}, {"url": "https://git.kernel.org/stable/c/b2662e7593e94ae09b1cf7ee5f09160a3612bcb2", "tags": ["Patch"], "source": "416baaa9-dc9f-4396-8d5f-8c081fb06d67"}], "vulnStatus": "Modified", "weaknesses": [{"type": "Primary", "source": "nvd@nist.gov", "description": [{"lang": "en", "value": "CWE-416"}]}, {"type": "Secondary", "source": "134c704f-9b21-4f2e-91b3-4a467353bcc0", "description": [{"lang": "en", "value": "CWE-416"}]}], "descriptions": [{"lang": "en", "value": "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."}, {"lang": "es", "value": "En el kernel de Linux, la siguiente vulnerabilidad ha sido resuelta:\n\nnet: nexthop: corregir uso despu\u00e9s de liberaci\u00f3n percpu en remove_nh_grp_entry\n\nAl eliminar un nexthop de un grupo, remove_nh_grp_entry() publica el nuevo grupo a trav\u00e9s de rcu_assign_pointer() y luego libera inmediatamente las estad\u00edsticas percpu de la entrada eliminada con free_percpu(). Sin embargo, el per\u00edodo de gracia de synchronize_net() en la funci\u00f3n llamadora remove_nexthop_from_groups() se ejecuta despu\u00e9s de la liberaci\u00f3n. Los lectores RCU que entraron antes de la publicaci\u00f3n todav\u00eda ven el grupo antiguo y pueden desreferenciar las estad\u00edsticas liberadas a trav\u00e9s de nh_grp_entry_stats_inc() -> get_cpu_ptr(nhge -> stats), causando un uso despu\u00e9s de liberaci\u00f3n en memoria percpu.\n\nSoluci\u00f3n: aplazar el free_percpu() hasta despu\u00e9s de synchronize_net() en la funci\u00f3n llamadora. Las entradas eliminadas se encadenan a trav\u00e9s de nh_list a una lista local de liberaci\u00f3n diferida. Despu\u00e9s de que el per\u00edodo de gracia se complete y todos los lectores RCU hayan terminado, las estad\u00edsticas percpu se liberan de forma segura."}], "lastModified": "2026-11-11T20:10:00.273", "configurations": [{"nodes": [{"negate": false, "cpeMatch": [{"criteria": "cpe:2.3:o:linux:linux_kernel:*:*:*:*:*:*:*:*", "vulnerable": true, "matchCriteriaId": "D1D90B78-24E3-418D-A238-3FE23C32239B", "versionEndExcluding": "6.12.78", "versionStartIncluding": "6.9"}, {"criteria": "cpe:2.3:o:linux:linux_kernel:*:*:*:*:*:*:*:*", "vulnerable": true, "matchCriteriaId": "D394AC60-6F28-435F-872A-CCDF384B8331", "versionEndExcluding": "6.18.19", "versionStartIncluding": "6.13"}, {"criteria": "cpe:2.3:o:linux:linux_kernel:*:*:*:*:*:*:*:*", "vulnerable": true, "matchCriteriaId": "E825E7C3-FEAC-4FD3-8A81-78D7387948C9", "versionEndExcluding": "6.19.9", "versionStartIncluding": "6.19"}, {"criteria": "cpe:2.3:o:linux:linux_kernel:6.9:-:*:*:*:*:*:*", "vulnerable": true, "matchCriteriaId": "3F2A4A3D-068A-4CF2-A09F-9C7937DDB0A5"}, {"criteria": "cpe:2.3:o:linux:linux_kernel:7.0:rc1:*:*:*:*:*:*", "vulnerable": true, "matchCriteriaId": "F253B622-8837-4245-BCE5-A7BF8FC76A16"}, {"criteria": "cpe:2.3:o:linux:linux_kernel:7.0:rc2:*:*:*:*:*:*", "vulnerable": true, "matchCriteriaId": "4AE85AD8-4641-4E7C-A2F4-305E2CD9EE64"}, {"criteria": "cpe:2.3:o:linux:linux_kernel:7.0:rc3:*:*:*:*:*:*", "vulnerable": true, "matchCriteriaId": "F666C8D8-6538-46D4-B318-87610DE64C34"}], "operator": "OR"}]}], "sourceIdentifier": "416baaa9-dc9f-4396-8d5f-8c081fb06d67"}