{
  "id": "CVE-2021-26829",
  "url": "https://spydr.io/cve/CVE-2021-26829",
  "published": "2021-06-11T12:15:12.053Z",
  "modified": "2026-06-17T03:43:50.063Z",
  "score": 5.4,
  "severity": "medium",
  "cvss_version": "3.1",
  "vector": "CVSS:3.1/AV:N/AC:L/PR:L/UI:R/S:C/C:L/I:L/A:N",
  "score_source": "NVD",
  "epss": 0.4805,
  "epss_percentile": 0.98824,
  "exploited": true,
  "kev": {
    "added": "2025-11-28",
    "due": "2025-12-19",
    "action": "Apply mitigations per vendor instructions, follow applicable BOD 22-01 guidance for cloud services, or discontinue use of the product if mitigations are unavailable.",
    "ransomware": "Unknown",
    "name": "OpenPLC ScadaBR Cross-site Scripting Vulnerability",
    "notes": "This vulnerability could affect an open-source component, third-party library, protocol, or proprietary implementation that could be used by different products. For more information, please see: https://github.com/SCADA-LTS/Scada-LTS/pull/3211 ; https://nvd.nist.gov/vuln/detail/CVE-2021-26829"
  },
  "ssvc_exploitation": "active",
  "vendors": [
    "scadabr"
  ],
  "products": [
    "scadabr"
  ],
  "cwes": [
    "CWE-79"
  ],
  "description": "OpenPLC ScadaBR through 0.9.1 on Linux and through 1.12.4 on Windows allows stored XSS via system_settings.shtm.",
  "status": "Analyzed",
  "score_type": "Primary",
  "scores": {
    "cvss_v40": null,
    "cvss_v31": 5.4,
    "cvss_v30": null
  },
  "references": [
    {
      "url": "http://forum.scadabr.com.br/t/report-falhas-de-seguranca-em-versoes-do-scadabr/3615/4",
      "tags": [
        "Vendor Advisory"
      ]
    },
    {
      "url": "https://youtu.be/Xh6LPCiLMa8",
      "tags": [
        "Exploit",
        "Third Party Advisory"
      ]
    },
    {
      "url": "https://www.cisa.gov/known-exploited-vulnerabilities-catalog?field_cve=CVE-2021-26829",
      "tags": [
        "US Government Resource"
      ]
    },
    {
      "url": "https://www.forescout.com/blog/anatomy-of-a-hacktivist-attack-russian-aligned-group-targets-otics/",
      "tags": [
        "Third Party Advisory"
      ]
    }
  ],
  "nvd_url": "https://nvd.nist.gov/vuln/detail/CVE-2021-26829",
  "covered_in": [],
  "attribution": [
    {
      "source": "NVD",
      "url": "https://nvd.nist.gov",
      "notice": "This product uses data from the NVD API but is not endorsed or certified by the NVD."
    },
    {
      "source": "CISA KEV",
      "url": "https://www.cisa.gov/known-exploited-vulnerabilities-catalog",
      "notice": "Known exploited vulnerabilities from the CISA KEV catalog."
    },
    {
      "source": "FIRST EPSS",
      "url": "https://www.first.org/epss",
      "notice": "Exploit prediction scores from FIRST EPSS."
    }
  ]
}