{
  "cveId": "CVE-2026-64578",
  "url": "https://patchblox.com/security/cve/CVE-2026-64578",
  "summary": "CVE-2026-64578 is fixed in 2 products on 1 platform, first by DEBIAN-CVE-2026-64578, released August 7, 2026. It is not reported as exploited. Patch Radar priority: High.",
  "title": "linux: In the Linux kernel, the following vulnerability has been resolved:  ksmbd: validate compound request size before rea...",
  "description": "In the Linux kernel, the following vulnerability has been resolved:  ksmbd: validate compound request size before reading StructureSize2  When ksmbd validates a compound (chained) SMB2 request, ksmbd_smb2_check_message() reads pdu-\u003EStructureSize2 without first checking that the compound element is large enough to contain it. StructureSize2 is a 2-byte field at offset 64 (__SMB2_HEADER_STRUCTURE_SIZE) from the start of each element.  The compound-walking logic only guarantees that a full 64-byte SMB2 header is present for the trailing element: when NextCommand is 0, len is reduced to the number of bytes remaining after next_smb2_rcv_hdr_off. A remote client can craft a compound request whose last element has exactly 64 bytes, so the 2-byte StructureSize2 read at offset 64 extends one byte past the receive buffer, producing a slab-out-of-bounds read.    BUG: KASAN: slab-out-of-bounds in ksmbd_smb2_check_message (fs/smb/server/smb2misc.c:402)   Read of size 2 at addr ffff888012ae31ac by task kworker/0:1/14   The buggy address is located 172 bytes inside of allocated 173-byte region   Workqueue: ksmbd-io handle_ksmbd_work   Call Trace:    ...    kasan_report (mm/kasan/report.c:595)    ksmbd_smb2_check_message (fs/smb/server/smb2misc.c:402)    handle_ksmbd_work (fs/smb/server/server.c:119)    process_one_work (kernel/workqueue.c:3314)    worker_thread (kernel/workqueue.c:3397)    kthread (kernel/kthread.c:436)    ret_from_fork (arch/x86/kernel/process.c:158)    ret_from_fork_asm (arch/x86/entry/entry_64.S:245)  Reject any compound element that is too small to hold StructureSize2 before dereferencing it.",
  "published": "2026-08-05T08:16:37Z",
  "severity": "high",
  "cvss": 8.2,
  "cvssVector": "CVSS:3.1/AV:N/AC:L/PR:N/UI:N/S:U/C:L/I:N/A:H",
  "epss": 0.00336,
  "epssPercentile": 0.27148,
  "priority": "High",
  "priorityTier": 3,
  "exploited": false,
  "vendorExploited": false,
  "disclosed": false,
  "fixes": [
    {
      "platform": "linux",
      "product": "linux",
      "release": "Debian 12.15 (bookworm)",
      "fixedVersion": "6.1.187-1",
      "fix": "DEBIAN-CVE-2026-64578",
      "url": "https://patchblox.com/security/fix/linux/debian-cve-2026-64578",
      "released": "2026-08-07T15:22:10Z"
    },
    {
      "platform": "linux",
      "product": "linux",
      "release": "Debian 13.5 (trixie)",
      "fixedVersion": "6.12.101-1",
      "fix": "DEBIAN-CVE-2026-64578",
      "url": "https://patchblox.com/security/fix/linux/debian-cve-2026-64578",
      "released": "2026-08-07T15:22:10Z"
    },
    {
      "platform": "linux",
      "product": "linux",
      "release": "Debian 14",
      "fixedVersion": "7.1.6-1",
      "fix": "DEBIAN-CVE-2026-64578",
      "url": "https://patchblox.com/security/fix/linux/debian-cve-2026-64578",
      "released": "2026-08-07T15:22:10Z"
    },
    {
      "platform": "linux",
      "product": "linux-6.12",
      "release": "Debian 12.15 (bookworm)",
      "fixedVersion": "6.12.101-1~deb12u1",
      "fix": "DEBIAN-CVE-2026-64578",
      "url": "https://patchblox.com/security/fix/linux/debian-cve-2026-64578",
      "released": "2026-08-07T15:22:10Z"
    }
  ],
  "noFixYet": [],
  "dataAsOf": "2026-11-08T19:12:23Z",
  "attribution": {
    "text": "Data: Patchblox Patch Radar",
    "url": "https://patchblox.com/security/patch-radar",
    "terms": "https://patchblox.com/security/patch-radar/use-the-data"
  }
}