FKIE_CVE-2026-63833

Vulnerability from fkie_nvd - Published: 2026-07-19 12:16 - Updated: 2026-07-20 15:16
Severity
7.1 (High) - CVSS:3.1/AV:L/AC:L/PR:L/UI:N/S:U/C:H/I:H/A:N
Summary
In the Linux kernel, the following vulnerability has been resolved: ntfs3: reject direct userspace writes to reserved $LX* xattrs NTFS3 uses $LXUID, $LXGID, $LXMOD and $LXDEV as internal WSL permission metadata and reloads them into i_uid, i_gid and i_mode from ntfs_get_wsl_perm(). Because the empty-prefix xattr handler also lets file owners call setxattr() on these names directly, an unprivileged writer on a writable ntfs3 mount can plant root ownership and S_ISUID on their own file and gain euid 0 after inode reload. Reject direct userspace writes to the reserved $LX* names. Internal ntfs3 metadata updates are unchanged because ntfs_save_wsl_perm() writes them via ntfs_set_ea() directly. [almaz.alexandrovich@paragon-software.com: added an additional check for non privileged users]
References
416baaa9-dc9f-4396-8d5f-8c081fb06d67https://git.kernel.org/stable/c/293a84fa40b3a1b3471c0545722724bc10973f76
416baaa9-dc9f-4396-8d5f-8c081fb06d67https://git.kernel.org/stable/c/2c3cd6da4a14380ef79e34bd9dff7caf46687477
416baaa9-dc9f-4396-8d5f-8c081fb06d67https://git.kernel.org/stable/c/5b08dccecf825cbf905f348bc6ccb497507e28e2
416baaa9-dc9f-4396-8d5f-8c081fb06d67https://git.kernel.org/stable/c/5e658b9245a52d838ef93729a7bc07de8e19deb7
416baaa9-dc9f-4396-8d5f-8c081fb06d67https://git.kernel.org/stable/c/e574af95234afc3c725988bbc1fdeb46b9f386a4
416baaa9-dc9f-4396-8d5f-8c081fb06d67https://git.kernel.org/stable/c/e8852ae29868e449fdb47eebc28f35fb80741a5f
416baaa9-dc9f-4396-8d5f-8c081fb06d67https://git.kernel.org/stable/c/f8d420949b335a4b51d06ab276beee6b8dfdc909
Impacted products
Vendor Product Version
To clipboard 

{
  "affected": [
    {
      "affectedData": [
        {
          "defaultStatus": "unaffected",
          "product": "Linux",
          "programFiles": [
            "fs/ntfs3/xattr.c"
          ],
          "repo": "https://git.kernel.org/pub/scm/linux/kernel/git/stable/linux.git",
          "vendor": "Linux",
          "versions": [
            {
              "lessThan": "e574af95234afc3c725988bbc1fdeb46b9f386a4",
              "status": "affected",
              "version": "be71b5cba2e6485e8959da7a9f9a44461a1bb074",
              "versionType": "git"
            },
            {
              "lessThan": "2c3cd6da4a14380ef79e34bd9dff7caf46687477",
              "status": "affected",
              "version": "be71b5cba2e6485e8959da7a9f9a44461a1bb074",
              "versionType": "git"
            },
            {
              "lessThan": "e8852ae29868e449fdb47eebc28f35fb80741a5f",
              "status": "affected",
              "version": "be71b5cba2e6485e8959da7a9f9a44461a1bb074",
              "versionType": "git"
            },
            {
              "lessThan": "f8d420949b335a4b51d06ab276beee6b8dfdc909",
              "status": "affected",
              "version": "be71b5cba2e6485e8959da7a9f9a44461a1bb074",
              "versionType": "git"
            },
            {
              "lessThan": "5e658b9245a52d838ef93729a7bc07de8e19deb7",
              "status": "affected",
              "version": "be71b5cba2e6485e8959da7a9f9a44461a1bb074",
              "versionType": "git"
            },
            {
              "lessThan": "293a84fa40b3a1b3471c0545722724bc10973f76",
              "status": "affected",
              "version": "be71b5cba2e6485e8959da7a9f9a44461a1bb074",
              "versionType": "git"
            },
            {
              "lessThan": "5b08dccecf825cbf905f348bc6ccb497507e28e2",
              "status": "affected",
              "version": "be71b5cba2e6485e8959da7a9f9a44461a1bb074",
              "versionType": "git"
            }
          ]
        },
        {
          "defaultStatus": "affected",
          "product": "Linux",
          "programFiles": [
            "fs/ntfs3/xattr.c"
          ],
          "repo": "https://git.kernel.org/pub/scm/linux/kernel/git/stable/linux.git",
          "vendor": "Linux",
          "versions": [
            {
              "status": "affected",
              "version": "5.15"
            },
            {
              "lessThan": "5.15",
              "status": "unaffected",
              "version": "0",
              "versionType": "semver"
            },
            {
              "lessThanOrEqual": "5.15.*",
              "status": "unaffected",
              "version": "5.15.211",
              "versionType": "semver"
            },
            {
              "lessThanOrEqual": "6.1.*",
              "status": "unaffected",
              "version": "6.1.177",
              "versionType": "semver"
            },
            {
              "lessThanOrEqual": "6.6.*",
              "status": "unaffected",
              "version": "6.6.144",
              "versionType": "semver"
            },
            {
              "lessThanOrEqual": "6.12.*",
              "status": "unaffected",
              "version": "6.12.95",
              "versionType": "semver"
            },
            {
              "lessThanOrEqual": "6.18.*",
              "status": "unaffected",
              "version": "6.18.38",
              "versionType": "semver"
            },
            {
              "lessThanOrEqual": "7.1.*",
              "status": "unaffected",
              "version": "7.1.3",
              "versionType": "semver"
            },
            {
              "lessThanOrEqual": "*",
              "status": "unaffected",
              "version": "7.2-rc1",
              "versionType": "original_commit_for_fix"
            }
          ]
        }
      ],
      "source": "416baaa9-dc9f-4396-8d5f-8c081fb06d67"
    }
  ],
  "cveTags": [],
  "descriptions": [
    {
      "lang": "en",
      "value": "In the Linux kernel, the following vulnerability has been resolved:\n\nntfs3: reject direct userspace writes to reserved $LX* xattrs\n\nNTFS3 uses $LXUID, $LXGID, $LXMOD and $LXDEV as internal WSL\npermission metadata and reloads them into i_uid, i_gid and i_mode\nfrom ntfs_get_wsl_perm().\n\nBecause the empty-prefix xattr handler also lets file owners call\nsetxattr() on these names directly, an unprivileged writer on a\nwritable ntfs3 mount can plant root ownership and S_ISUID on their own\nfile and gain euid 0 after inode reload.\n\nReject direct userspace writes to the reserved $LX* names. Internal\nntfs3 metadata updates are unchanged because ntfs_save_wsl_perm()\nwrites them via ntfs_set_ea() directly.\n\n[almaz.alexandrovich@paragon-software.com: added an additional check for non privileged users]"
    }
  ],
  "id": "CVE-2026-63833",
  "lastModified": "2026-07-20T15:16:50.050",
  "metrics": {
    "cvssMetricV31": [
      {
        "cvssData": {
          "attackComplexity": "LOW",
          "attackVector": "LOCAL",
          "availabilityImpact": "NONE",
          "baseScore": 7.1,
          "baseSeverity": "HIGH",
          "confidentialityImpact": "HIGH",
          "integrityImpact": "HIGH",
          "privilegesRequired": "LOW",
          "scope": "UNCHANGED",
          "userInteraction": "NONE",
          "vectorString": "CVSS:3.1/AV:L/AC:L/PR:L/UI:N/S:U/C:H/I:H/A:N",
          "version": "3.1"
        },
        "exploitabilityScore": 1.8,
        "impactScore": 5.2,
        "source": "416baaa9-dc9f-4396-8d5f-8c081fb06d67",
        "type": "Secondary"
      }
    ]
  },
  "published": "2026-07-19T12:16:56.713",
  "references": [
    {
      "source": "416baaa9-dc9f-4396-8d5f-8c081fb06d67",
      "url": "https://git.kernel.org/stable/c/293a84fa40b3a1b3471c0545722724bc10973f76"
    },
    {
      "source": "416baaa9-dc9f-4396-8d5f-8c081fb06d67",
      "url": "https://git.kernel.org/stable/c/2c3cd6da4a14380ef79e34bd9dff7caf46687477"
    },
    {
      "source": "416baaa9-dc9f-4396-8d5f-8c081fb06d67",
      "url": "https://git.kernel.org/stable/c/5b08dccecf825cbf905f348bc6ccb497507e28e2"
    },
    {
      "source": "416baaa9-dc9f-4396-8d5f-8c081fb06d67",
      "url": "https://git.kernel.org/stable/c/5e658b9245a52d838ef93729a7bc07de8e19deb7"
    },
    {
      "source": "416baaa9-dc9f-4396-8d5f-8c081fb06d67",
      "url": "https://git.kernel.org/stable/c/e574af95234afc3c725988bbc1fdeb46b9f386a4"
    },
    {
      "source": "416baaa9-dc9f-4396-8d5f-8c081fb06d67",
      "url": "https://git.kernel.org/stable/c/e8852ae29868e449fdb47eebc28f35fb80741a5f"
    },
    {
      "source": "416baaa9-dc9f-4396-8d5f-8c081fb06d67",
      "url": "https://git.kernel.org/stable/c/f8d420949b335a4b51d06ab276beee6b8dfdc909"
    }
  ],
  "sourceIdentifier": "416baaa9-dc9f-4396-8d5f-8c081fb06d67",
  "vulnStatus": "Received"
}



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