smb: client: validate dacloffset before building DACL pointers_CVE-2026-46195

{
    "lastseen": "",
    "description": "In the Linux kernel, the following vulnerability has been resolved:\n\nsmb: client: validate dacloffset before building DACL pointers\n\nparse_sec_desc(), build_sec_desc(), and the chown path in\nid_mode_to_cifs_acl() all add the server-supplied dacloffset to pntsd\nbefore proving a DACL header fits inside the returned security\ndescriptor.\n\nOn 32-bit builds a malicious server can return dacloffset near\nU32_MAX, wrap the derived DACL pointer below end_of_acl, and then slip\npast the later pointer-based bounds checks. build_sec_desc() and\nid_mode_to_cifs_acl() can then dereference DACL fields from the wrapped\npointer in the chmod/chown rewrite paths.\n\nValidate dacloffset numerically before building any DACL pointer and\nreuse the same helper at the three DACL entry points.",
    "published": "2026-05-28T09:36:48.259Z",
    "modified": "2026-05-30T10:48:55.662Z",
    "type": "cve",
    "title": "smb: client: validate dacloffset before building DACL pointers",
    "source": "Linux",
    "references": "https://git.kernel.org/stable/c/ba7f71b6161c0943dafc367565e5843d16b7d505\nhttps://git.kernel.org/stable/c/3b1ddba19e77ee35241cd27f16dc3e8d14e08db7\nhttps://git.kernel.org/stable/c/c688f3ed73d31943334ad2139cb02ec49664322a\nhttps://git.kernel.org/stable/c/8bd07e417b6bda67e317920584e48cb6ee442a8a\nhttps://git.kernel.org/stable/c/f98b48151cc502ada59d9778f0112d21f2586ca3",
    "id": "CVE-2026-46195",
    "bulletinFamily": "",
    "cwe": null,
    "cvelist": null,
    "sourceData": "Linux Linux bc3e9dd9d104ca1b75644eab87b38ce8a924aef4\nLinux Linux bc3e9dd9d104ca1b75644eab87b38ce8a924aef4\nLinux Linux bc3e9dd9d104ca1b75644eab87b38ce8a924aef4\nLinux Linux bc3e9dd9d104ca1b75644eab87b38ce8a924aef4\nLinux Linux bc3e9dd9d104ca1b75644eab87b38ce8a924aef4\nLinux Linux 5.12",
    "sourceHref": "",
    "cvss": {
        "score": 9.8,
        "severity": "CRITICAL",
        "vector": "CVSS:3.1/AV:N/AC:L/PR:N/UI:N/S:U/C:H/I:H/A:H",
        "version": "3.1"
    },
    "cvss2": [],
    "cvss3": {
        "version": "",
        "vectorString": "",
        "baseScore": 0,
        "baseSeverity": "",
        "attackVector": "",
        "attackComplexity": "",
        "privilegesRequired": "",
        "userInteraction": "",
        "scope": "",
        "confidentialityImpact": "",
        "integrityImpact": "",
        "availabilityImpact": "",
        "cvssV3": {
            "version": "",
            "vectorString": "",
            "baseScore": 0,
            "baseSeverity": "",
            "attackVector": "",
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            "privilegesRequired": "",
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            "scope": "",
            "confidentialityImpact": "",
            "integrityImpact": "",
            "availabilityImpact": ""
        }
    },
    "href": "",
    "category_name": "CVE",
    "post_link": "",
    "product": "Linux",
    "version": "bc3e9dd9d104ca1b75644eab87b38ce8a924aef4",
    "vendor": "Linux",
    "ai_description": "",
    "ai_severity": "",
    "ai_vendor": "",
    "ai_product": "",
    "ai_version": "",
    "ai_score": 0
}