Vulnerability-Lookup

GHSA-WV5H-JX62-4XCV

Vulnerability from github – Published: 2026-07-19 12:30 – Updated: 2026-07-20 15:31

Details

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]

Severity

7.1 (High)


                  
                    CVSS:3.1/AV:L/AC:L/PR:L/UI:N/S:U/C:H/I:H/A:N

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{
  "affected": [],
  "aliases": [
    "CVE-2026-63833"
  ],
  "database_specific": {
    "cwe_ids": [],
    "github_reviewed": false,
    "github_reviewed_at": null,
    "nvd_published_at": "2026-07-19T12:16:56Z",
    "severity": "HIGH"
  },
  "details": "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": "GHSA-wv5h-jx62-4xcv",
  "modified": "2026-07-20T15:31:47Z",
  "published": "2026-07-19T12:30:24Z",
  "references": [
    {
      "type": "ADVISORY",
      "url": "https://nvd.nist.gov/vuln/detail/CVE-2026-63833"
    },
    {
      "type": "WEB",
      "url": "https://git.kernel.org/stable/c/293a84fa40b3a1b3471c0545722724bc10973f76"
    },
    {
      "type": "WEB",
      "url": "https://git.kernel.org/stable/c/2c3cd6da4a14380ef79e34bd9dff7caf46687477"
    },
    {
      "type": "WEB",
      "url": "https://git.kernel.org/stable/c/5b08dccecf825cbf905f348bc6ccb497507e28e2"
    },
    {
      "type": "WEB",
      "url": "https://git.kernel.org/stable/c/5e658b9245a52d838ef93729a7bc07de8e19deb7"
    },
    {
      "type": "WEB",
      "url": "https://git.kernel.org/stable/c/e574af95234afc3c725988bbc1fdeb46b9f386a4"
    },
    {
      "type": "WEB",
      "url": "https://git.kernel.org/stable/c/e8852ae29868e449fdb47eebc28f35fb80741a5f"
    },
    {
      "type": "WEB",
      "url": "https://git.kernel.org/stable/c/f8d420949b335a4b51d06ab276beee6b8dfdc909"
    }
  ],
  "schema_version": "1.4.0",
  "severity": [
    {
      "score": "CVSS:3.1/AV:L/AC:L/PR:L/UI:N/S:U/C:H/I:H/A:N",
      "type": "CVSS_V3"
    }
  ]
}

CVE-2026-63833 (GCVE-0-2026-63833)

Vulnerability from cvelistv5 – Published: 2026-07-19 12:02 – Updated: 2026-07-20 13:40

Title

ntfs3: reject direct userspace writes to reserved $LX* xattrs

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]

Severity

7.1 (High)


                        
                          CVSS:3.1/AV:L/AC:L/PR:L/UI:N/S:U/C:H/I:H/A:N

Assigner

Linux

References

7 references

URL	Tags
https://git.kernel.org/stable/c/e574af95234afc3c7…
https://git.kernel.org/stable/c/2c3cd6da4a14380ef…
https://git.kernel.org/stable/c/e8852ae29868e449f…
https://git.kernel.org/stable/c/f8d420949b335a4b5…
https://git.kernel.org/stable/c/5e658b9245a52d838…
https://git.kernel.org/stable/c/293a84fa40b3a1b34…
https://git.kernel.org/stable/c/5b08dccecf825cbf9…

Impacted products

2 products

Vendor	Product	Version
Linux	Linux	Affected: be71b5cba2e6485e8959da7a9f9a44461a1bb074 , < e574af95234afc3c725988bbc1fdeb46b9f386a4 (git) Affected: be71b5cba2e6485e8959da7a9f9a44461a1bb074 , < 2c3cd6da4a14380ef79e34bd9dff7caf46687477 (git) Affected: be71b5cba2e6485e8959da7a9f9a44461a1bb074 , < e8852ae29868e449fdb47eebc28f35fb80741a5f (git) Affected: be71b5cba2e6485e8959da7a9f9a44461a1bb074 , < f8d420949b335a4b51d06ab276beee6b8dfdc909 (git) Affected: be71b5cba2e6485e8959da7a9f9a44461a1bb074 , < 5e658b9245a52d838ef93729a7bc07de8e19deb7 (git) Affected: be71b5cba2e6485e8959da7a9f9a44461a1bb074 , < 293a84fa40b3a1b3471c0545722724bc10973f76 (git) Affected: be71b5cba2e6485e8959da7a9f9a44461a1bb074 , < 5b08dccecf825cbf905f348bc6ccb497507e28e2 (git)
Linux	Linux	Affected: 5.15 Unaffected: 0 , < 5.15 (semver) Unaffected: 5.15.211 , ≤ 5.15.* (semver) Unaffected: 6.1.177 , ≤ 6.1.* (semver) Unaffected: 6.6.144 , ≤ 6.6.* (semver) Unaffected: 6.12.95 , ≤ 6.12.* (semver) Unaffected: 6.18.38 , ≤ 6.18.* (semver) Unaffected: 7.1.3 , ≤ 7.1.* (semver) Unaffected: 7.2-rc1 , ≤ * (original_commit_for_fix)

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          "programFiles": [
            "fs/ntfs3/xattr.c"
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              "status": "unaffected",
              "version": "5.15.211",
              "versionType": "semver"
            },
            {
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              "status": "unaffected",
              "version": "6.1.177",
              "versionType": "semver"
            },
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              "lessThanOrEqual": "6.6.*",
              "status": "unaffected",
              "version": "6.6.144",
              "versionType": "semver"
            },
            {
              "lessThanOrEqual": "6.12.*",
              "status": "unaffected",
              "version": "6.12.95",
              "versionType": "semver"
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              "lessThanOrEqual": "6.18.*",
              "status": "unaffected",
              "version": "6.18.38",
              "versionType": "semver"
            },
            {
              "lessThanOrEqual": "7.1.*",
              "status": "unaffected",
              "version": "7.1.3",
              "versionType": "semver"
            },
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              "lessThanOrEqual": "*",
              "status": "unaffected",
              "version": "7.2-rc1",
              "versionType": "original_commit_for_fix"
            }
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Sightings

Author	Source	Type	Date	Other

Nomenclature

Seen: The vulnerability was mentioned, discussed, or observed by the user.
Confirmed: The vulnerability has been validated from an analyst's perspective.
Published Proof of Concept: A public proof of concept is available for this vulnerability.
Exploited: The vulnerability was observed as exploited by the user who reported the sighting.
Patched: The vulnerability was observed as successfully patched by the user who reported the sighting.
Not exploited: The vulnerability was not observed as exploited by the user who reported the sighting.
Not confirmed: The user expressed doubt about the validity of the vulnerability.
Not patched: The vulnerability was not observed as successfully patched by the user who reported the sighting.

Detection rules are retrieved from Rulezet.

Action not permitted

GHSA-WV5H-JX62-4XCV

CVE-2026-63833 (GCVE-0-2026-63833)

Tags

Sightings

Nomenclature