{
    "dataType": "CVE_RECORD",
    "dataVersion": "5.2",
    "cveMetadata": {
        "cveId": "CVE-2026-43438",
        "assignerOrgId": "416baaa9-dc9f-4396-8d5f-8c081fb06d67",
        "state": "PUBLISHED",
        "assignerShortName": "Linux",
        "dateReserved": "2026-05-01T14:12:56.009Z",
        "datePublished": "2026-05-08T14:22:07.980Z",
        "dateUpdated": "2026-08-05T12:27:56.866Z"
    },
    "containers": {
        "cna": {
            "providerMetadata": {
                "orgId": "416baaa9-dc9f-4396-8d5f-8c081fb06d67",
                "shortName": "Linux",
                "dateUpdated": "2026-08-05T12:27:56.866Z"
            },
            "descriptions": [
                {
                    "lang": "en",
                    "value": "In the Linux kernel, the following vulnerability has been resolved:\n\nsched_ext: Remove redundant css_put() in scx_cgroup_init()\n\nThe iterator css_for_each_descendant_pre() walks the cgroup hierarchy\nunder cgroup_lock(). It does not increment the reference counts on\nyielded css structs.\n\nAccording to the cgroup documentation, css_put() should only be used\nto release a reference obtained via css_get() or css_tryget_online().\nSince the iterator does not use either of these to acquire a reference,\ncalling css_put() in the error path of scx_cgroup_init() causes a\nrefcount underflow.\n\nRemove the unbalanced css_put() to prevent a potential Use-After-Free\n(UAF) vulnerability."
                }
            ],
            "metrics": [
                {
                    "cvssV3_1": {
                        "version": "3.1",
                        "vectorString": "CVSS:3.1/AV:L/AC:L/PR:L/UI:N/S:U/C:H/I:H/A:H",
                        "baseScore": 7.8,
                        "baseSeverity": "HIGH"
                    },
                    "scenarios": [
                        {
                            "lang": "en",
                            "value": "AV:L - The vulnerable path is reached from local userspace through BPF struct_ops scheduler registration and cgroup state, not by remote packets or adjacent/physical input.\nAC:L - An attacker with the needed BPF access can provide an ops.cgroup_init() callback that succeeds for root and fails for an existing non-root cgroup, directly triggering the bad error path without winning a race.\nPR:L - Loading and attaching sched_ext BPF struct_ops requires local BPF privileges, but these can be delegated via BPF tokens/user-namespace based capability checks in plausible deployments, so this is not necessarily real init-namespace root.\nUI:N - After the attacker has local access and the required BPF ability, exploitation is performed by their own syscalls and does not require a victim user action.\nS:U - The bug corrupts kernel cgroup/scheduler state within the same kernel security authority; it is not a VM escape or another explicit scope boundary crossing.\nC:H - The redundant css_put() can underflow the css refcount and lead to use-after-free of cgroup/task_group state, which is memory corruption that can plausibly enable kernel memory disclosure.\nI:H - A use-after-free in kernel heap-managed scheduler/cgroup objects can plausibly be shaped into arbitrary write or control-flow corruption, so integrity impact is high.\nA:H - Even without full exploitation, the refcount underflow/UAF can corrupt live kernel cgroup state and cause warnings, crashes, or panics."
                        }
                    ]
                }
            ],
            "affected": [
                {
                    "product": "Linux",
                    "vendor": "Linux",
                    "defaultStatus": "unaffected",
                    "repo": "https://git.kernel.org/pub/scm/linux/kernel/git/stable/linux.git",
                    "programFiles": [
                        "kernel/sched/ext.c"
                    ],
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                        {
                            "version": "8195136669661fdfe54e9a8923c33b31c92fc1da",
                            "lessThan": "cc095cd305fddbe25a968e4a78436ff9476cf0f6",
                            "status": "affected",
                            "versionType": "git"
                        },
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                            "lessThan": "6eaaa67d6998f6c30c462b140db8c062e07ec473",
                            "status": "affected",
                            "versionType": "git"
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                        {
                            "version": "8195136669661fdfe54e9a8923c33b31c92fc1da",
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                            "status": "affected",
                            "versionType": "git"
                        },
                        {
                            "version": "8195136669661fdfe54e9a8923c33b31c92fc1da",
                            "lessThan": "1336b579f6079fb8520be03624fcd9ba443c930b",
                            "status": "affected",
                            "versionType": "git"
                        }
                    ]
                },
                {
                    "product": "Linux",
                    "vendor": "Linux",
                    "defaultStatus": "affected",
                    "repo": "https://git.kernel.org/pub/scm/linux/kernel/git/stable/linux.git",
                    "programFiles": [
                        "kernel/sched/ext.c"
                    ],
                    "versions": [
                        {
                            "version": "6.12",
                            "status": "affected"
                        },
                        {
                            "version": "0",
                            "lessThan": "6.12",
                            "status": "unaffected",
                            "versionType": "semver"
                        },
                        {
                            "version": "6.12.78",
                            "lessThanOrEqual": "6.12.*",
                            "status": "unaffected",
                            "versionType": "semver"
                        },
                        {
                            "version": "6.18.19",
                            "lessThanOrEqual": "6.18.*",
                            "status": "unaffected",
                            "versionType": "semver"
                        },
                        {
                            "version": "6.19.9",
                            "lessThanOrEqual": "6.19.*",
                            "status": "unaffected",
                            "versionType": "semver"
                        },
                        {
                            "version": "7.0",
                            "lessThanOrEqual": "*",
                            "status": "unaffected",
                            "versionType": "original_commit_for_fix"
                        }
                    ]
                }
            ],
            "cpeApplicability": [
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                    "nodes": [
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                            "negate": false,
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                                    "vulnerable": true,
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                                },
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            "references": [
                {
                    "url": "https://git.kernel.org/stable/c/cc095cd305fddbe25a968e4a78436ff9476cf0f6"
                },
                {
                    "url": "https://git.kernel.org/stable/c/6eaaa67d6998f6c30c462b140db8c062e07ec473"
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                {
                    "url": "https://git.kernel.org/stable/c/bf50f3285eda8a0173625fcdb5f183f96e1008cd"
                },
                {
                    "url": "https://git.kernel.org/stable/c/1336b579f6079fb8520be03624fcd9ba443c930b"
                }
            ],
            "title": "sched_ext: Remove redundant css_put() in scx_cgroup_init()",
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