smb: client: require a full NFS mode SID before reading mode bits_CVE-2026-43350

{
    "lastseen": "",
    "description": "In the Linux kernel, the following vulnerability has been resolved:\n\nsmb: client: require a full NFS mode SID before reading mode bits\n\nparse_dacl() treats an ACE SID matching sid_unix_NFS_mode as an NFS\nmode SID and reads sid.sub_auth[2] to recover the mode bits.\n\nThat assumes the ACE carries three subauthorities, but compare_sids()\nonly compares min(a, b) subauthorities.  A malicious server can return\nan ACE with num_subauth = 2 and sub_auth[] = {88, 3}, which still\nmatches sid_unix_NFS_mode and then drives the sub_auth[2] read four\nbytes past the end of the ACE.\n\nRequire num_subauth >= 3 before treating the ACE as an NFS mode SID.\nThis keeps the fix local to the special-SID mode path without changing\ncompare_sids() semantics for the rest of cifsacl.",
    "published": "2026-05-08T13:41:53.276Z",
    "modified": "2026-05-11T06:33:32.916Z",
    "type": "cve",
    "title": "smb: client: require a full NFS mode SID before reading mode bits",
    "source": "Linux",
    "references": "https://git.kernel.org/stable/c/b53b8e98c23310294fc45fc686db5ee860311896\nhttps://git.kernel.org/stable/c/c8eef12af1cc73031639ea7cf16e0b10e2536b0b\nhttps://git.kernel.org/stable/c/38a69f08ee82c450d3e4168707fff2e317dc3ff7\nhttps://git.kernel.org/stable/c/f8488c07bea2431ee12a6067d736578064fa46b4\nhttps://git.kernel.org/stable/c/2757ad3e4b6f9e0fed4c7739594e702abc5cab21",
    "id": "CVE-2026-43350",
    "bulletinFamily": "",
    "cwe": null,
    "cvelist": null,
    "sourceData": "Linux Linux e2f8fbfb8d09c06decde162090fac3ee220aa280\nLinux Linux e2f8fbfb8d09c06decde162090fac3ee220aa280\nLinux Linux e2f8fbfb8d09c06decde162090fac3ee220aa280\nLinux Linux e2f8fbfb8d09c06decde162090fac3ee220aa280\nLinux Linux e2f8fbfb8d09c06decde162090fac3ee220aa280\nLinux Linux 5.4",
    "sourceHref": "",
    "cvss": {
        "score": 7.6,
        "severity": "HIGH",
        "vector": "CVSS:3.1/AV:N/AC:L/PR:N/UI:R/S:U/C:L/I:L/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": "",
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            "privilegesRequired": "",
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        }
    },
    "href": "",
    "category_name": "CVE",
    "post_link": "",
    "product": "Linux",
    "version": "e2f8fbfb8d09c06decde162090fac3ee220aa280",
    "vendor": "Linux",
    "ai_description": "",
    "ai_severity": "",
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    "ai_score": 0
}