Security advisory

{
  "id": "07ebf963870679ed1c06957631ae654f434580f9d9885f4b812ec1813d08d9e1",
  "url": "https://osv.dev/vulnerability/CVE-2020-8421",
  "method": "structured",
  "payload": {
    "kind": "advisory",
    "title": "CVE-2020-8421",
    "summary": "An issue was discovered in Joomla! before 3.9.15. Inadequate escaping of usernames allows XSS attacks in com_actionlogs.",
    "evidence": "osv:CVE-2020-8421",
    "products": [],
    "severity": "medium",
    "structured": {
      "id": "CVE-2020-8421",
      "aliases": [
        "BIT-joomla-2020-8421",
        "CVE-2020-8421"
      ],
      "metrics": [
        {
          "type": "CVSS_V3",
          "score": "CVSS:3.1/AV:N/AC:L/PR:N/UI:R/S:C/C:L/I:L/A:N"
        }
      ],
      "affected": [
        {
          "ranges": [
            {
              "repo": "https://github.com/joomla/joomla-cms",
              "type": "GIT",
              "events": [
                {
                  "introduced": "a2b9beda71c3603b0f0da0ab70bb30cd976ec123"
                },
                {
                  "fixed": "e5dc4beb39b7edbbd4eec187dad7162798b77da2"
                }
              ],
              "database_specific": {
                "extracted_events": [
                  {
                    "cpe": "cpe:2.3:a:joomla:joomla\\!:*:*:*:*:*:*:*:*",
                    "range": [
                      {
                        "introduced": "3.9.0"
                      },
                      {
                        "fixed": "3.9.14"
                      }
                    ],
                    "source": "CPE_RANGE"
                  }
                ]
              }
            }
          ],
          "versions": [
            "3.9.14-rc",
            "3.9.13",
            "3.9.12",
            "3.9.13-rc2",
            "3.9.13-rc",
            "3.9.12-rc",
            "3.9.11",
            "3.9.10",
            "3.9.8",
            "3.9.11-rc",
            "3.9.9",
            "3.9.6",
            "3.9.5",
            "3.9.9-rc",
            "3.9.4",
            "3.9.3",
            "3.9.7",
            "3.9.7-rc",
            "3.9.2-rc",
            "3.9.1",
            "3.9.6-rc2",
            "3.9.6-rc",
            "3.9.0",
            "3.9.5-rc",
            "3.9.4-rc",
            "3.9.3-rc",
            "3.9.2",
            "3.9.1-rc"
          ],
          "database_specific": {
            "source": "https://storage.googleapis.com/cve-osv-conversion/osv-output/CVE-2020-8421.json"
          }
        }
      ],
      "modified": "2026-10-24T10:30:25.097196926Z",
      "provider": "osv",
      "references": [
        "https://developer.joomla.org/security-centre/800-20200103-core-xss-in-com-actionlogs"
      ],
      "provider_metadata": {}
    },
    "related_cves": [
      {
        "value": "CVE-2020-8421",
        "evidence": "/id"
      }
    ],
    "security_relevant": true,
    "severity_evidence": "/severity/0/score"
  },
  "source_id": "core-osv",
  "document_id": 431282,
  "published_at": "2020-01-28T21:15:12.123+00:00"
}