{
  "slug": "cure53",
  "category": "security-audit-firms",
  "name": "Cure53",
  "description": "Berlin security firm that performs penetration tests and source code audits of web, mobile, browser, VPN and cryptographic software, and publishes many client reports.",
  "website": "https://cure53.de",
  "license": null,
  "platforms": [],
  "jurisdiction": {
    "code": "DE",
    "name": "Germany",
    "eyes": "Fourteen Eyes",
    "eu": true,
    "gdpr": true,
    "cloud_act": null
  },
  "pick": true,
  "pick_reason": "Publishes a large public library of full audit reports, many for open-source and privacy projects, and maintains the DOMPurify sanitizer. Its website uses no cookies or analytics.",
  "disclosure": null,
  "grade": "A",
  "score": 100,
  "coverage": 100,
  "summary": "Cure53 scores 100 out of 100 (grade A) on the security audit firms criteria. It meets 4 of 4 criteria: publishes full reports, audits open-source projects, public research and no trackers on website. It is based in Germany: Fourteen Eyes member; EU member (GDPR). Automated tests: SSL Labs grade A+ and Mozilla HTTP Observatory grade B.",
  "url": "https://privacyratings.com/security-audit-firms/cure53/",
  "markdown": "https://privacyratings.com/security-audit-firms/cure53/index.md",
  "answers": {
    "public_reports": {
      "title": "Publishes full reports",
      "weight": 3,
      "answer": "yes",
      "evidence": "https://cure53.de/#publications-anchor",
      "note": "The publications section links many full client reports as PDFs."
    },
    "open_source_work": {
      "title": "Audits open-source projects",
      "weight": 2,
      "answer": "yes",
      "evidence": "https://cure53.de/pentest-report_psiphon-conduit-library.pdf",
      "note": "Published reports cover many open-source projects, such as Psiphon, Mullvad VPN and KeePassium."
    },
    "public_research": {
      "title": "Public research",
      "weight": 1,
      "answer": "yes",
      "evidence": "https://github.com/cure53/DOMPurify",
      "note": "Maintains the open-source DOMPurify sanitizer and publishes research papers on browser and web security."
    },
    "no_trackers": {
      "title": "No trackers on website",
      "weight": 1,
      "answer": "yes",
      "evidence": "https://cure53.de/datenschutz.php",
      "note": "The privacy policy states the site uses no cookies and no user analytics, and the tracker test found none."
    }
  },
  "tests": {
    "ssllabs": "A+",
    "observatory": "B",
    "internetnl_web": null,
    "internetnl_mail": null,
    "trackers": [],
    "tested_at": "2026-10-01T07:07:13.901Z"
  },
  "last_modified": "2026-10-01T07:44:20Z"
}