{
  "affected": [
    {
      "ranges": [
        {
          "events": [
            {
              "introduced": "e2f34481b24db2fd634b5edb0a5bd0e4d38cc6e9"
            },
            {
              "fixed": "3127a884525dc8ca4def73254bfcd3ccef0bf812"
            },
            {
              "fixed": "de9eb0b44fa9123170e6245b49638e0e453c10f8"
            },
            {
              "fixed": "aef151bcfa494bfe983669de2726734b534adb73"
            },
            {
              "fixed": "cc57232cae23c0df91b4a59d0f519141ce9b5b02"
            }
          ],
          "repo": "https://git.kernel.org/pub/scm/linux/kernel/git/stable/linux.git",
          "type": "GIT"
        }
      ]
    },
    {
      "package": {
        "ecosystem": "Linux",
        "name": "Kernel"
      },
      "ranges": [
        {
          "events": [
            {
              "introduced": "5.15.0"
            },
            {
              "fixed": "6.6.143"
            }
          ],
          "type": "ECOSYSTEM"
        },
        {
          "events": [
            {
              "introduced": "6.7.0"
            },
            {
              "fixed": "6.18.35"
            }
          ],
          "type": "ECOSYSTEM"
        },
        {
          "events": [
            {
              "introduced": "6.19.0"
            },
            {
              "fixed": "7.0.12"
            }
          ],
          "type": "ECOSYSTEM"
        }
      ]
    }
  ],
  "database_specific": {
    "cna_assigner": "Linux",
    "osv_generated_from": "https://github.com/CVEProject/cvelistV5/tree/main/cves/2026/52xxx/CVE-2026-52944.json"
  },
  "details": "In the Linux kernel, the following vulnerability has been resolved:\n\nksmbd: fix FSCTL permission bypass by adding a permission check for FSCTL_SET_SPARSE\n\nFSCTL_SET_SPARSE in fsctl_set_sparse() modifies the file's sparse\nattribute and saves it through xattr without any permission checks.\n\nThis exposes two issues:\n\n1) A client on a read-only share can change the sparse attribute\n   on files it opened, even though the share is read-only.\n   Other FSCTL write operations already check\n   test_tree_conn_flag(work-\u003etcon, KSMBD_TREE_CONN_FLAG_WRITABLE),\n   but FSCTL_SET_SPARSE does not.\n\n2) Even on writable shares, clients without FILE_WRITE_DATA or\n   FILE_WRITE_ATTRIBUTES access should not modify the sparse\n   attribute. Similar handle-level checks exist in other functions\n   but are missing here.\n\nAdd both share-level writable check and per-handle access check.\nUse goto out on error to avoid leaking file references.",
  "id": "CVE-2026-52944",
  "modified": "2026-07-10T03:53:46.203784578Z",
  "published": "2026-06-24T09:59:09.149Z",
  "references": [
    {
      "type": "WEB",
      "url": "https://git.kernel.org/stable/c/3127a884525dc8ca4def73254bfcd3ccef0bf812"
    },
    {
      "type": "WEB",
      "url": "https://git.kernel.org/stable/c/aef151bcfa494bfe983669de2726734b534adb73"
    },
    {
      "type": "WEB",
      "url": "https://git.kernel.org/stable/c/cc57232cae23c0df91b4a59d0f519141ce9b5b02"
    },
    {
      "type": "WEB",
      "url": "https://git.kernel.org/stable/c/de9eb0b44fa9123170e6245b49638e0e453c10f8"
    },
    {
      "type": "ADVISORY",
      "url": "https://github.com/CVEProject/cvelistV5/tree/main/cves/2026/52xxx/CVE-2026-52944.json"
    },
    {
      "type": "ADVISORY",
      "url": "https://nvd.nist.gov/vuln/detail/CVE-2026-52944"
    },
    {
      "type": "PACKAGE",
      "url": "https://git.kernel.org/pub/scm/linux/kernel/git/stable/linux.git"
    }
  ],
  "schema_version": "1.7.5",
  "summary": "ksmbd: fix FSCTL permission bypass by adding a permission check for FSCTL_SET_SPARSE"
}