{
  "cveId": "CVE-2026-64293",
  "url": "https://patchblox.com/security/cve/CVE-2026-64293",
  "summary": "CVE-2026-64293 is fixed in 20 products on 1 platform, first by ALAS2023-2026-2045, released August 3, 2026. It is not reported as exploited. Patch Radar priority: High.",
  "title": "linux: In the Linux kernel, the following vulnerability has been resolved:  iommufd: Use sizeof(*hdr) instead of sizeof(hdr)...",
  "description": "In the Linux kernel, the following vulnerability has been resolved:  iommufd: Use sizeof(*hdr) instead of sizeof(hdr) in veventq read  The bound-check in iommufd_veventq_fops_read() for the normal vEVENT path uses sizeof(hdr) where the surrounding code uses sizeof(*hdr):  \tif (!vevent_for_lost_events_header(cur) \u0026\u0026 \t    sizeof(hdr) \u002B cur-\u003Edata_len \u003E count - done) {  hdr is declared as struct iommufd_vevent_header *, so sizeof(hdr) evaluates to the size of the pointer.  Surrounding code uses sizeof(*hdr) consistently:  \tif (done \u003E= count || sizeof(*hdr) \u003E count - done) { \t... \tif (copy_to_user(buf \u002B done, hdr, sizeof(*hdr))) { \t... \tdone \u002B= sizeof(*hdr);  struct iommufd_vevent_header is currently 8 bytes (two __u32 fields, flags and sequence), so on 64-bit (sizeof(void *) == 8) the two expressions happen to be equal and the check works as intended.  On 32-bit (sizeof(void *) == 4) the check under-counts the header by 4 bytes: a vEVENT whose data_len causes 8 \u002B cur-\u003Edata_len to exceed count - done while 4 \u002B cur-\u003Edata_len does not will pass the check, then the loop will copy_to_user 8 bytes of header followed by data_len bytes of payload, writing past the user-supplied buffer.  It is also a latent bug for any future expansion of struct iommufd_vevent_header beyond sizeof(void *) on 64-bit; the check should not depend on the type happening to match the host pointer width.  Use sizeof(*hdr) to match the rest of the function and the actual amount that will be copied.",
  "published": "2026-07-25T10:17:10Z",
  "severity": "high",
  "cvss": 7.8,
  "cvssVector": "CVSS:3.1/AV:L/AC:L/PR:L/UI:N/S:U/C:H/I:H/A:H",
  "epss": 0.00173,
  "epssPercentile": 0.06814,
  "priority": "High",
  "priorityTier": 3,
  "exploited": false,
  "vendorExploited": false,
  "disclosed": false,
  "fixes": [
    {
      "platform": "linux",
      "product": "bpftool6.18",
      "release": "amzn 2023",
      "fixedVersion": "1:6.18.39-79.141.amzn2023",
      "fix": "ALAS2023-2026-2045",
      "url": "https://patchblox.com/security/fix/linux/alas2023-2026-2045",
      "released": "2026-08-03T09:00:00Z"
    },
    {
      "platform": "linux",
      "product": "bpftool6.18-debuginfo",
      "release": "amzn 2023",
      "fixedVersion": "1:6.18.39-79.141.amzn2023",
      "fix": "ALAS2023-2026-2045",
      "url": "https://patchblox.com/security/fix/linux/alas2023-2026-2045",
      "released": "2026-08-03T09:00:00Z"
    },
    {
      "platform": "linux",
      "product": "kernel-livepatch-6.18.39-79.141",
      "release": "amzn 2023",
      "fixedVersion": "1:1.0-0.amzn2023",
      "fix": "ALAS2023-2026-2045",
      "url": "https://patchblox.com/security/fix/linux/alas2023-2026-2045",
      "released": "2026-08-03T09:00:00Z"
    },
    {
      "platform": "linux",
      "product": "kernel6.18",
      "release": "amzn 2023",
      "fixedVersion": "1:6.18.39-79.141.amzn2023",
      "fix": "ALAS2023-2026-2045",
      "url": "https://patchblox.com/security/fix/linux/alas2023-2026-2045",
      "released": "2026-08-03T09:00:00Z"
    },
    {
      "platform": "linux",
      "product": "kernel6.18-debuginfo",
      "release": "amzn 2023",
      "fixedVersion": "1:6.18.39-79.141.amzn2023",
      "fix": "ALAS2023-2026-2045",
      "url": "https://patchblox.com/security/fix/linux/alas2023-2026-2045",
      "released": "2026-08-03T09:00:00Z"
    },
    {
      "platform": "linux",
      "product": "kernel6.18-debuginfo-common-aarch64",
      "release": "amzn 2023",
      "fixedVersion": "1:6.18.39-79.141.amzn2023",
      "fix": "ALAS2023-2026-2045",
      "url": "https://patchblox.com/security/fix/linux/alas2023-2026-2045",
      "released": "2026-08-03T09:00:00Z"
    },
    {
      "platform": "linux",
      "product": "kernel6.18-debuginfo-common-x86_64",
      "release": "amzn 2023",
      "fixedVersion": "1:6.18.39-79.141.amzn2023",
      "fix": "ALAS2023-2026-2045",
      "url": "https://patchblox.com/security/fix/linux/alas2023-2026-2045",
      "released": "2026-08-03T09:00:00Z"
    },
    {
      "platform": "linux",
      "product": "kernel6.18-devel",
      "release": "amzn 2023",
      "fixedVersion": "1:6.18.39-79.141.amzn2023",
      "fix": "ALAS2023-2026-2045",
      "url": "https://patchblox.com/security/fix/linux/alas2023-2026-2045",
      "released": "2026-08-03T09:00:00Z"
    },
    {
      "platform": "linux",
      "product": "kernel6.18-headers",
      "release": "amzn 2023",
      "fixedVersion": "1:6.18.39-79.141.amzn2023",
      "fix": "ALAS2023-2026-2045",
      "url": "https://patchblox.com/security/fix/linux/alas2023-2026-2045",
      "released": "2026-08-03T09:00:00Z"
    },
    {
      "platform": "linux",
      "product": "kernel6.18-modules-extra",
      "release": "amzn 2023",
      "fixedVersion": "1:6.18.39-79.141.amzn2023",
      "fix": "ALAS2023-2026-2045",
      "url": "https://patchblox.com/security/fix/linux/alas2023-2026-2045",
      "released": "2026-08-03T09:00:00Z"
    },
    {
      "platform": "linux",
      "product": "kernel6.18-modules-extra-common",
      "release": "amzn 2023",
      "fixedVersion": "1:6.18.39-79.141.amzn2023",
      "fix": "ALAS2023-2026-2045",
      "url": "https://patchblox.com/security/fix/linux/alas2023-2026-2045",
      "released": "2026-08-03T09:00:00Z"
    },
    {
      "platform": "linux",
      "product": "kernel6.18-tools",
      "release": "amzn 2023",
      "fixedVersion": "1:6.18.39-79.141.amzn2023",
      "fix": "ALAS2023-2026-2045",
      "url": "https://patchblox.com/security/fix/linux/alas2023-2026-2045",
      "released": "2026-08-03T09:00:00Z"
    },
    {
      "platform": "linux",
      "product": "kernel6.18-tools-debuginfo",
      "release": "amzn 2023",
      "fixedVersion": "1:6.18.39-79.141.amzn2023",
      "fix": "ALAS2023-2026-2045",
      "url": "https://patchblox.com/security/fix/linux/alas2023-2026-2045",
      "released": "2026-08-03T09:00:00Z"
    },
    {
      "platform": "linux",
      "product": "kernel6.18-tools-devel",
      "release": "amzn 2023",
      "fixedVersion": "1:6.18.39-79.141.amzn2023",
      "fix": "ALAS2023-2026-2045",
      "url": "https://patchblox.com/security/fix/linux/alas2023-2026-2045",
      "released": "2026-08-03T09:00:00Z"
    },
    {
      "platform": "linux",
      "product": "linux",
      "release": "Debian 14",
      "fixedVersion": "7.1.4-1",
      "fix": "DEBIAN-CVE-2026-64293",
      "url": "https://patchblox.com/security/fix/linux/debian-cve-2026-64293",
      "released": "2026-08-07T15:22:10Z"
    },
    {
      "platform": "linux",
      "product": "microvm-kernel6.18",
      "release": "amzn 2023",
      "fixedVersion": "1:6.18.39-79.141.amzn2023",
      "fix": "ALAS2023-2026-2045",
      "url": "https://patchblox.com/security/fix/linux/alas2023-2026-2045",
      "released": "2026-08-03T09:00:00Z"
    },
    {
      "platform": "linux",
      "product": "perf6.18",
      "release": "amzn 2023",
      "fixedVersion": "1:6.18.39-79.141.amzn2023",
      "fix": "ALAS2023-2026-2045",
      "url": "https://patchblox.com/security/fix/linux/alas2023-2026-2045",
      "released": "2026-08-03T09:00:00Z"
    },
    {
      "platform": "linux",
      "product": "perf6.18-debuginfo",
      "release": "amzn 2023",
      "fixedVersion": "1:6.18.39-79.141.amzn2023",
      "fix": "ALAS2023-2026-2045",
      "url": "https://patchblox.com/security/fix/linux/alas2023-2026-2045",
      "released": "2026-08-03T09:00:00Z"
    },
    {
      "platform": "linux",
      "product": "python3-perf6.18",
      "release": "amzn 2023",
      "fixedVersion": "1:6.18.39-79.141.amzn2023",
      "fix": "ALAS2023-2026-2045",
      "url": "https://patchblox.com/security/fix/linux/alas2023-2026-2045",
      "released": "2026-08-03T09:00:00Z"
    },
    {
      "platform": "linux",
      "product": "python3-perf6.18-debuginfo",
      "release": "amzn 2023",
      "fixedVersion": "1:6.18.39-79.141.amzn2023",
      "fix": "ALAS2023-2026-2045",
      "url": "https://patchblox.com/security/fix/linux/alas2023-2026-2045",
      "released": "2026-08-03T09:00:00Z"
    }
  ],
  "noFixYet": [],
  "dataAsOf": "2026-11-08T00:53:09Z",
  "attribution": {
    "text": "Data: Patchblox Patch Radar",
    "url": "https://patchblox.com/security/patch-radar",
    "terms": "https://patchblox.com/security/patch-radar/use-the-data"
  }
}