{
    "dataType": "CVE_RECORD",
    "dataVersion": "5.2",
    "cveMetadata": {
        "cveId": "CVE-2026-64138",
        "assignerOrgId": "416baaa9-dc9f-4396-8d5f-8c081fb06d67",
        "state": "PUBLISHED",
        "assignerShortName": "Linux",
        "dateReserved": "2026-07-19T07:54:57.037Z",
        "datePublished": "2026-07-19T15:40:31.760Z",
        "dateUpdated": "2026-08-05T12:39:39.447Z"
    },
    "containers": {
        "cna": {
            "providerMetadata": {
                "orgId": "416baaa9-dc9f-4396-8d5f-8c081fb06d67",
                "shortName": "Linux",
                "dateUpdated": "2026-08-05T12:39:39.447Z"
            },
            "descriptions": [
                {
                    "lang": "en",
                    "value": "In the Linux kernel, the following vulnerability has been resolved:\n\nksmbd: validate SID in parent security descriptor during ACL inheritance\n\nIntroduce smb_validate_ntsd_sid() helper to safely validate Owner SID\nand Group SID inside the NT Security Descriptor (smb_ntsd) retrieved\nfrom the parent directory."
                }
            ],
            "metrics": [
                {
                    "cvssV3_1": {
                        "version": "3.1",
                        "vectorString": "CVSS:3.1/AV:N/AC:L/PR:L/UI:N/S:U/C:H/I:H/A:H",
                        "baseScore": 8.8,
                        "baseSeverity": "HIGH"
                    },
                    "scenarios": [
                        {
                            "lang": "en",
                            "value": "AV:N - The vulnerable code runs in ksmbd's in-kernel SMB server, reachable by remote attackers sending SMB2 CREATE requests over TCP port 445 after session establishment.\nAC:L - An authenticated attacker with share write access can plant a malformed parent security.NTACL xattr and reliably trigger the bug by creating a child file; they control both the crafted on-disk descriptor and the concurrent SMB request that exercises inheritance.\nPR:L - Exploitation requires an authenticated SMB2 session with write permission on the parent directory to create files; this is not a pre-authentication code path but does not require host root or special kernel capabilities.\nUI:N - Exploitation is fully automated over the SMB protocol and does not require any action from a separate victim user beyond normal server operation.\nS:U - The vulnerability is confined to the kernel's ksmbd security context and does not cross a VM, container, or IOMMU security boundary.\nC:H - The unchecked SID size computation and memcpy perform an out-of-bounds kernel heap read; stolen memory can be embedded in the newly created file's security descriptor and retrieved by the attacker.\nI:H - Unvalidated out-of-bounds memory access is a memory corruption primitive in kernel context; per kernel CVSS guidance, such bugs are scored at High integrity impact even when the immediate fault is a read.\nA:H - Reading from attacker-controlled out-of-bounds offsets can dereference unmapped or invalid kernel memory, causing an oops or panic and denying SMB service."
                        }
                    ]
                }
            ],
            "affected": [
                {
                    "product": "Linux",
                    "vendor": "Linux",
                    "defaultStatus": "unaffected",
                    "repo": "https://git.kernel.org/pub/scm/linux/kernel/git/stable/linux.git",
                    "programFiles": [
                        "fs/smb/server/smbacl.c"
                    ],
                    "versions": [
                        {
                            "version": "e2f34481b24db2fd634b5edb0a5bd0e4d38cc6e9",
                            "lessThan": "f0e5c9c663badc9982e6941322eef1cb17de0f11",
                            "status": "affected",
                            "versionType": "git"
                        },
                        {
                            "version": "e2f34481b24db2fd634b5edb0a5bd0e4d38cc6e9",
                            "lessThan": "18d8db24b0a5b7be4829238dd4022236df02d421",
                            "status": "affected",
                            "versionType": "git"
                        },
                        {
                            "version": "e2f34481b24db2fd634b5edb0a5bd0e4d38cc6e9",
                            "lessThan": "1c9d0646a9959752f11ca1080dc1ff26bd1756cb",
                            "status": "affected",
                            "versionType": "git"
                        },
                        {
                            "version": "e2f34481b24db2fd634b5edb0a5bd0e4d38cc6e9",
                            "lessThan": "69f030cf95488ae1186c72ac8c66fd279664ea7f",
                            "status": "affected",
                            "versionType": "git"
                        }
                    ]
                },
                {
                    "product": "Linux",
                    "vendor": "Linux",
                    "defaultStatus": "affected",
                    "repo": "https://git.kernel.org/pub/scm/linux/kernel/git/stable/linux.git",
                    "programFiles": [
                        "fs/smb/server/smbacl.c"
                    ],
                    "versions": [
                        {
                            "version": "5.15",
                            "status": "affected"
                        },
                        {
                            "version": "0",
                            "lessThan": "5.15",
                            "status": "unaffected",
                            "versionType": "semver"
                        },
                        {
                            "version": "6.12.92",
                            "lessThanOrEqual": "6.12.*",
                            "status": "unaffected",
                            "versionType": "semver"
                        },
                        {
                            "version": "6.18.34",
                            "lessThanOrEqual": "6.18.*",
                            "status": "unaffected",
                            "versionType": "semver"
                        },
                        {
                            "version": "7.0.11",
                            "lessThanOrEqual": "7.0.*",
                            "status": "unaffected",
                            "versionType": "semver"
                        },
                        {
                            "version": "7.1",
                            "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": "5.15",
                                    "versionEndExcluding": "6.12.92"
                                },
                                {
                                    "vulnerable": true,
                                    "criteria": "cpe:2.3:o:linux:linux_kernel:*:*:*:*:*:*:*:*",
                                    "versionStartIncluding": "5.15",
                                    "versionEndExcluding": "6.18.34"
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                                    "criteria": "cpe:2.3:o:linux:linux_kernel:*:*:*:*:*:*:*:*",
                                    "versionStartIncluding": "5.15",
                                    "versionEndExcluding": "7.0.11"
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                                    "criteria": "cpe:2.3:o:linux:linux_kernel:*:*:*:*:*:*:*:*",
                                    "versionStartIncluding": "5.15",
                                    "versionEndExcluding": "7.1"
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            "references": [
                {
                    "url": "https://git.kernel.org/stable/c/f0e5c9c663badc9982e6941322eef1cb17de0f11"
                },
                {
                    "url": "https://git.kernel.org/stable/c/18d8db24b0a5b7be4829238dd4022236df02d421"
                },
                {
                    "url": "https://git.kernel.org/stable/c/1c9d0646a9959752f11ca1080dc1ff26bd1756cb"
                },
                {
                    "url": "https://git.kernel.org/stable/c/69f030cf95488ae1186c72ac8c66fd279664ea7f"
                }
            ],
            "title": "ksmbd: validate SID in parent security descriptor during ACL inheritance",
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}