correct buffer checks for DM_OP hypercalls

{
  "dataType": "CVE_RECORD",
  "dataVersion": "5.2",
  "cveMetadata": {
    "cveId": "CVE-2026-62433",
    "assignerOrgId": "23aa2041-22e1-471f-9209-9b7396fa234f",
    "assignerShortName": "XEN",
    "dateUpdated": "2026-07-28T13:34:15.160Z",
    "dateReserved": "2026-07-14T10:28:12.655Z",
    "datePublished": "2026-07-28T12:32:59.802Z",
    "state": "PUBLISHED"
  },
  "containers": {
    "cna": {
      "providerMetadata": {
        "orgId": "23aa2041-22e1-471f-9209-9b7396fa234f",
        "shortName": "XEN",
        "dateUpdated": "2026-07-28T12:32:59.802Z"
      },
      "datePublic": "2026-07-28T12:00:00.000Z",
      "title": "correct buffer checks for DM_OP hypercalls",
      "descriptions": [
        {
          "lang": "en",
          "value": "Parts of the DM_OP handling code assumes the caller has provided the\nrequired number of buffers for the given operation without any checking\nbeing done.  As a result, certain operations might access stack\nrubble as structures are possibly uninitialized."
        }
      ],
      "affected": [
        {
          "vendor": "Xen",
          "product": "Xen",
          "defaultStatus": "unknown",
          "versions": [
            {
              "version": "consult Xen advisory XSA-506",
              "status": "unknown"
            }
          ]
        }
      ],
      "references": [
        {
          "url": "https://xenbits.xenproject.org/xsa/advisory-506.html"
        }
      ],
      "impacts": [
        {
          "descriptions": [
            {
              "lang": "en",
              "value": "A device model of a HVM guest can gain insight on the contents of the\nXen stack, thus possibly leaking data from other guests contexts."
            }
          ]
        }
      ],
      "configurations": [
        {
          "lang": "en",
          "value": "All Xen versions from 4.10 onwards are vulnerable.  Xen versions 4.9 and\nearlier are not vulnerable.\n\nOnly entities controlling HVM guests can leverage the vulnerability.\nThese are device models running in either a stub domain or de-privileged\nin Dom0."
        }
      ],
      "workarounds": [
        {
          "lang": "en",
          "value": "Running only PV or PVH guests will avoid the vulnerability.\n\n(Switching from a device model stub domain or a de-privileged device\nmodel to a fully privileged Dom0 device model does NOT mitigate this\nvulnerability.  Rather, it simply recategorises the vulnerability to\nhostile management code, regarding it \"as designed\"; thus it merely\nreclassifies these issues as \"not a bug\".  The security of a Xen system\nusing stub domains is still better than with a qemu-dm running as a Dom0\nprocess.  Users and vendors of stub qemu dm systems should not change\ntheir configuration to use a Dom0 QEMU process.)"
        }
      ]
    },
    "adp": [
      {
        "providerMetadata": {
          "orgId": "af854a3a-2127-422b-91ae-364da2661108",
          "shortName": "CVE",
          "dateUpdated": "2026-07-28T13:34:15.160Z"
        },
        "title": "CVE Program Container",
        "references": [
          {
            "url": "http://xenbits.xen.org/xsa/advisory-506.html"
          }
        ]
      }
    ]
  }
}