Security advisory

{
  "id": "ad6503a575b20a49dcd4bae9cc3aca03ac601c55860a6ea2e2bee5c73e8b9487",
  "url": "https://osv.dev/vulnerability/CVE-2020-18703",
  "method": "structured",
  "payload": {
    "kind": "advisory",
    "title": "CVE-2020-18703",
    "summary": "XML External Entities (XXE) in Quokka v0.4.0 allows remote attackers to execute arbitrary code via the component 'quokka/utils/atom.py'.",
    "evidence": "osv:CVE-2020-18703",
    "products": [],
    "severity": "critical",
    "structured": {
      "id": "CVE-2020-18703",
      "aliases": [
        "CVE-2020-18703",
        "GHSA-3xg5-6c3j-vp8x",
        "PYSEC-2021-144"
      ],
      "metrics": [
        {
          "type": "CVSS_V3",
          "score": "CVSS:3.1/AV:N/AC:L/PR:N/UI:N/S:U/C:H/I:H/A:H"
        }
      ],
      "affected": [
        {
          "ranges": [
            {
              "repo": "https://github.com/quokkaproject/quokka",
              "type": "GIT",
              "events": [
                {
                  "introduced": "25c753f2697e6d7228249b95dff9514c135bd04d"
                },
                {
                  "last_affected": "25c753f2697e6d7228249b95dff9514c135bd04d"
                }
              ],
              "database_specific": {
                "extracted_events": [
                  {
                    "cpe": "cpe:2.3:a:quokka_project:quokka:0.4.0:*:*:*:*:*:*:*",
                    "range": [
                      {
                        "introduced": "0.4.0"
                      },
                      {
                        "last_affected": "0.4.0"
                      }
                    ],
                    "source": "CPE_STRING"
                  }
                ]
              }
            }
          ],
          "versions": [
            "0.4.0"
          ],
          "database_specific": {
            "source": "https://storage.googleapis.com/cve-osv-conversion/osv-output/CVE-2020-18703.json"
          }
        }
      ],
      "modified": "2026-10-20T10:52:03.705662950Z",
      "provider": "osv",
      "references": [
        "https://github.com/rochacbruno/quokka/issues/676"
      ],
      "provider_metadata": {}
    },
    "related_cves": [
      {
        "value": "CVE-2020-18703",
        "evidence": "/id"
      }
    ],
    "security_relevant": true,
    "severity_evidence": "/severity/0/score"
  },
  "source_id": "core-osv",
  "document_id": 383246,
  "published_at": "2021-08-16T18:15:07.17+00:00"
}