{
  "schemaVersion": 1,
  "attribution": [
    {
      "source": "CISA Known Exploited Vulnerabilities",
      "url": "https://www.cisa.gov/known-exploited-vulnerabilities-catalog",
      "licence": "US government work"
    },
    {
      "source": "GitHub Advisory Database",
      "url": "https://github.com/advisories",
      "licence": "CC BY 4.0"
    },
    {
      "source": "Have I Been Pwned",
      "url": "https://haveibeenpwned.com/",
      "licence": "CC BY 4.0"
    },
    {
      "source": "CVE Program (CVE records)",
      "url": "https://www.cve.org/Legal/TermsOfUse",
      "licence": "CVE Terms of Use",
      "notice": "Copyright © 1999-2026, The MITRE Corporation. CVE is a trademark and the CVE logo is a registered trademark of The MITRE Corporation.",
      "terms": "CVE Usage: MITRE hereby grants you a perpetual, worldwide, non-exclusive, no-charge, royalty-free, irrevocable copyright license to reproduce, prepare derivative works of, publicly display, publicly perform, sublicense, and distribute Common Vulnerabilities and Exposures (CVE™). Any copy you make for such purposes is authorized provided that you reproduce MITRE's copyright designation and this license in any such copy."
    },
    {
      "source": "FIRST EPSS",
      "url": "https://www.first.org/epss/",
      "licence": "free to use; FIRST requests attribution"
    }
  ],
  "record": {
    "id": "CVE-2021-28698",
    "sourceURL": "https://www.cve.org/CVERecord?id=CVE-2021-28698",
    "idYear": 2021,
    "status": "PUBLISHED",
    "publishedAt": "2021-08-27T18:32:13.000Z",
    "updatedAt": "2024-08-03T21:47:33.154Z",
    "importedAt": "2026-10-24T01:56:26.894Z",
    "snapshot": {
      "id": "cve_2026-10-24_midnight_baseline",
      "at": "2026-10-24T00:00:00.000Z",
      "source": "https://github.com/CVEProject/cvelistV5/releases/tag/cve_2026-10-24_0100Z"
    },
    "facts": {
      "title": null,
      "summary": "long running loops in grant table handling In order to properly monitor resource use, Xen maintains information on the grant mappings a domain may create to map grants offered by other domains. In the process of carrying out certain actions, Xen would iterate over all such entries, including ones which aren't in use anymore and some which may have been created but never used. If the number of entries for a given domain is large enough, this iterating of the entire table may tie up a CPU for too long, starving other domains or causing issues in the hypervisor itself. Note that a domain may map its own grants, i.e. there is no need for multiple domains to be involved here. A pair of \"cooperating\" guests may, however, cause the effects to be more severe.",
      "affected": [
        {
          "vendor": "Xen",
          "product": "xen",
          "versions": [
            {
              "version": "4.14.x",
              "status": "affected"
            }
          ]
        },
        {
          "vendor": "Xen",
          "product": "xen",
          "versions": [
            {
              "version": "unspecified",
              "status": "unknown",
              "versionType": "custom",
              "lessThan": "4.12"
            },
            {
              "version": "4.15.x",
              "status": "affected",
              "versionType": "custom",
              "lessThan": "unspecified"
            },
            {
              "version": "next of xen-unstable",
              "status": "unaffected",
              "versionType": "custom",
              "lessThan": "unspecified"
            }
          ]
        },
        {
          "vendor": "Xen",
          "product": "xen",
          "versions": [
            {
              "version": "4.13.x",
              "status": "affected"
            }
          ]
        },
        {
          "vendor": "Xen",
          "product": "xen",
          "versions": [
            {
              "version": "4.11.x",
              "status": "affected"
            }
          ]
        },
        {
          "vendor": "Xen",
          "product": "xen",
          "versions": [
            {
              "version": "4.12.x",
              "status": "affected"
            }
          ]
        }
      ]
    }
  }
}