{
  "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-2026-20104",
    "sourceURL": "https://www.cve.org/CVERecord?id=CVE-2026-20104",
    "idYear": 2026,
    "status": "PUBLISHED",
    "publishedAt": "2026-03-25T16:05:17.530Z",
    "updatedAt": "2026-03-26T17:39:54.940Z",
    "importedAt": "2026-10-24T01:57:55.771Z",
    "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": "A vulnerability in the bootloader of Cisco IOS XE Software for Cisco Catalyst 9200 Series Switches, Cisco Catalyst ESS9300 Embedded Series Switches, Cisco Catalyst IE9310 and IE9320 Rugged Series Switches, and Cisco IE3500 and IE3505 Rugged Series Switches could allow an authenticated, local attacker with level-15 privileges or an unauthenticated attacker with physical access to an affected device to execute arbitrary code at boot time and break the chain of trust.\r\n\r This vulnerability is due to insufficient validation of software at boot time. An attacker could exploit this vulnerability by manipulating the loaded binaries on an affected device to bypass some of the integrity checks that are performed during the boot process. A successful exploit could allow the attacker to execute code that bypasses the requirement to run Cisco-signed images.\r\n\r Cisco has assigned this security advisory a Security Impact Rating (SIR) of High rather than Medium as the score indicates because this vulnerability allows an attacker to bypass a major security feature of a device.",
      "affected": [
        {
          "vendor": "Cisco",
          "product": "Cisco IOS XE Software",
          "versions": [
            {
              "version": "16.12.8",
              "status": "affected"
            },
            {
              "version": "16.12.6",
              "status": "affected"
            },
            {
              "version": "16.12.6a",
              "status": "affected"
            },
            {
              "version": "16.12.7",
              "status": "affected"
            },
            {
              "version": "17.3.3",
              "status": "affected"
            },
            {
              "version": "17.3.4",
              "status": "affected"
            },
            {
              "version": "17.3.5",
              "status": "affected"
            },
            {
              "version": "17.3.6",
              "status": "affected"
            },
            {
              "version": "17.3.4b",
              "status": "affected"
            },
            {
              "version": "17.3.7",
              "status": "affected"
            },
            {
              "version": "17.3.8",
              "status": "affected"
            },
            {
              "version": "17.3.8a",
              "status": "affected"
            },
            {
              "version": "17.4.1",
              "status": "affected"
            },
            {
              "version": "17.5.1",
              "status": "affected"
            },
            {
              "version": "17.6.1",
              "status": "affected"
            },
            {
              "version": "17.6.2",
              "status": "affected"
            },
            {
              "version": "17.6.3",
              "status": "affected"
            },
            {
              "version": "17.6.1y",
              "status": "affected"
            },
            {
              "version": "17.6.4",
              "status": "affected"
            },
            {
              "version": "17.6.5",
              "status": "affected"
            },
            {
              "version": "17.6.6",
              "status": "affected"
            },
            {
              "version": "17.6.6a",
              "status": "affected"
            },
            {
              "version": "17.6.5a",
              "status": "affected"
            },
            {
              "version": "17.6.7",
              "status": "affected"
            },
            {
              "version": "17.6.8",
              "status": "affected"
            },
            {
              "version": "17.7.1",
              "status": "affected"
            },
            {
              "version": "17.7.1a",
              "status": "affected"
            },
            {
              "version": "17.10.1",
              "status": "affected"
            },
            {
              "version": "17.8.1",
              "status": "affected"
            },
            {
              "version": "17.8.1a",
              "status": "affected"
            },
            {
              "version": "17.9.1",
              "status": "affected"
            },
            {
              "version": "17.9.2",
              "status": "affected"
            },
            {
              "version": "17.9.1a",
              "status": "affected"
            },
            {
              "version": "17.9.3",
              "status": "affected"
            },
            {
              "version": "17.9.4",
              "status": "affected"
            },
            {
              "version": "17.9.5",
              "status": "affected"
            },
            {
              "version": "17.9.4a",
              "status": "affected"
            },
            {
              "version": "17.9.5b",
              "status": "affected"
            },
            {
              "version": "17.9.6",
              "status": "affected"
            },
            {
              "version": "17.9.6a",
              "status": "affected"
            },
            {
              "version": "17.9.7",
              "status": "affected"
            },
            {
              "version": "17.9.8",
              "status": "affected"
            },
            {
              "version": "17.11.1",
              "status": "affected"
            },
            {
              "version": "17.12.1",
              "status": "affected"
            },
            {
              "version": "17.12.2",
              "status": "affected"
            },
            {
              "version": "17.12.3",
              "status": "affected"
            },
            {
              "version": "17.12.4",
              "status": "affected"
            },
            {
              "version": "17.12.5",
              "status": "affected"
            },
            {
              "version": "17.12.6",
              "status": "affected"
            },
            {
              "version": "17.13.1",
              "status": "affected"
            },
            {
              "version": "17.14.1",
              "status": "affected"
            },
            {
              "version": "17.15.1",
              "status": "affected"
            },
            {
              "version": "17.15.2",
              "status": "affected"
            },
            {
              "version": "17.15.3",
              "status": "affected"
            },
            {
              "version": "17.15.4",
              "status": "affected"
            },
            {
              "version": "17.16.1",
              "status": "affected"
            },
            {
              "version": "17.17.1",
              "status": "affected"
            },
            {
              "version": "17.18.1",
              "status": "affected"
            },
            {
              "version": "17.18.2",
              "status": "affected"
            }
          ]
        }
      ]
    }
  }
}