{
  "affected": [
    {
      "ranges": [
        {
          "events": [
            {
              "introduced": "e2f34481b24db2fd634b5edb0a5bd0e4d38cc6e9"
            },
            {
              "fixed": "2c307126ed8e7adddab82b8e31d962d3a2156ab1"
            },
            {
              "fixed": "f7550a91ab211726f59cb137523b7a9eae1ac6eb"
            },
            {
              "fixed": "f0e337e7db67cc1c832958bbb6c4026bdceacfdb"
            },
            {
              "fixed": "ea128f06d2fb2186f0cac0c9f3e953e4d1f5c29a"
            },
            {
              "fixed": "15b38176fd1530372905c602fde51fe89ec8c877"
            }
          ],
          "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": "6.6.148"
            }
          ],
          "type": "ECOSYSTEM"
        },
        {
          "events": [
            {
              "introduced": "6.7.0"
            },
            {
              "fixed": "6.12.101"
            }
          ],
          "type": "ECOSYSTEM"
        },
        {
          "events": [
            {
              "introduced": "6.13.0"
            },
            {
              "fixed": "6.18.42"
            }
          ],
          "type": "ECOSYSTEM"
        },
        {
          "events": [
            {
              "introduced": "6.19.0"
            },
            {
              "fixed": "7.1.6"
            }
          ],
          "type": "ECOSYSTEM"
        }
      ]
    }
  ],
  "database_specific": {
    "cna_assigner": "Linux",
    "osv_generated_from": "https://github.com/CVEProject/cvelistV5/tree/main/cves/2026/64xxx/CVE-2026-64578.json"
  },
  "details": "In the Linux kernel, the following vulnerability has been resolved:\n\nksmbd: validate compound request size before reading StructureSize2\n\nWhen ksmbd validates a compound (chained) SMB2 request,\nksmbd_smb2_check_message() reads pdu-\u003eStructureSize2 without first\nchecking that the compound element is large enough to contain it.\nStructureSize2 is a 2-byte field at offset 64\n(__SMB2_HEADER_STRUCTURE_SIZE) from the start of each element.\n\nThe compound-walking logic only guarantees that a full 64-byte SMB2\nheader is present for the trailing element: when NextCommand is 0, len is\nreduced to the number of bytes remaining after next_smb2_rcv_hdr_off. A\nremote client can craft a compound request whose last element has exactly\n64 bytes, so the 2-byte StructureSize2 read at offset 64 extends one byte\npast the receive buffer, producing a slab-out-of-bounds read.\n\n  BUG: KASAN: slab-out-of-bounds in ksmbd_smb2_check_message (fs/smb/server/smb2misc.c:402)\n  Read of size 2 at addr ffff888012ae31ac by task kworker/0:1/14\n  The buggy address is located 172 bytes inside of allocated 173-byte region\n  Workqueue: ksmbd-io handle_ksmbd_work\n  Call Trace:\n   ...\n   kasan_report (mm/kasan/report.c:595)\n   ksmbd_smb2_check_message (fs/smb/server/smb2misc.c:402)\n   handle_ksmbd_work (fs/smb/server/server.c:119)\n   process_one_work (kernel/workqueue.c:3314)\n   worker_thread (kernel/workqueue.c:3397)\n   kthread (kernel/kthread.c:436)\n   ret_from_fork (arch/x86/kernel/process.c:158)\n   ret_from_fork_asm (arch/x86/entry/entry_64.S:245)\n\nReject any compound element that is too small to hold StructureSize2\nbefore dereferencing it.",
  "id": "CVE-2026-64578",
  "modified": "2026-08-07T03:30:16.154219533Z",
  "published": "2026-08-05T08:09:33.740Z",
  "references": [
    {
      "type": "WEB",
      "url": "https://git.kernel.org/stable/c/15b38176fd1530372905c602fde51fe89ec8c877"
    },
    {
      "type": "WEB",
      "url": "https://git.kernel.org/stable/c/2c307126ed8e7adddab82b8e31d962d3a2156ab1"
    },
    {
      "type": "WEB",
      "url": "https://git.kernel.org/stable/c/ea128f06d2fb2186f0cac0c9f3e953e4d1f5c29a"
    },
    {
      "type": "WEB",
      "url": "https://git.kernel.org/stable/c/f0e337e7db67cc1c832958bbb6c4026bdceacfdb"
    },
    {
      "type": "WEB",
      "url": "https://git.kernel.org/stable/c/f7550a91ab211726f59cb137523b7a9eae1ac6eb"
    },
    {
      "type": "ADVISORY",
      "url": "https://github.com/CVEProject/cvelistV5/tree/main/cves/2026/64xxx/CVE-2026-64578.json"
    },
    {
      "type": "ADVISORY",
      "url": "https://nvd.nist.gov/vuln/detail/CVE-2026-64578"
    },
    {
      "type": "PACKAGE",
      "url": "https://git.kernel.org/pub/scm/linux/kernel/git/stable/linux.git"
    }
  ],
  "schema_version": "1.8.0",
  "summary": "ksmbd: validate compound request size before reading StructureSize2"
}