{
  "affected": [
    {
      "ranges": [
        {
          "database_specific": {
            "versions": [
              {
                "introduced": "15.10.0"
              },
              {
                "fixed": "20.8.8"
              }
            ]
          },
          "events": [
            {
              "introduced": "1625d4080339190682bc76bbe79ea26132accfda"
            },
            {
              "fixed": "5437fdf8f13adb9590f9f52616d9f69c3ee8db3c"
            }
          ],
          "repo": "https://github.com/capricorn86/happy-dom",
          "type": "GIT"
        }
      ]
    }
  ],
  "aliases": [
    "GHSA-6q6h-j7hj-3r64"
  ],
  "database_specific": {
    "cna_assigner": "GitHub_M",
    "cwe_ids": [
      "CWE-94"
    ],
    "osv_generated_from": "https://github.com/CVEProject/cvelistV5/tree/main/cves/2026/33xxx/CVE-2026-33943.json"
  },
  "details": "Happy DOM is a JavaScript implementation of a web browser without its graphical user interface. In versions 15.10.0 through 20.8.7, a code injection vulnerability in `ECMAScriptModuleCompiler` allows an attacker to achieve Remote Code Execution (RCE) by injecting arbitrary JavaScript expressions inside `export { }` declarations in ES module scripts processed by happy-dom. The compiler directly interpolates unsanitized content into generated code as an executable expression, and the quote filter does not strip backticks, allowing template literal-based payloads to bypass sanitization. Version 20.8.8 fixes the issue.",
  "id": "CVE-2026-33943",
  "modified": "2026-04-01T23:08:21.226960453Z",
  "published": "2026-03-27T21:15:19.186Z",
  "references": [
    {
      "type": "ADVISORY",
      "url": "https://github.com/CVEProject/cvelistV5/tree/main/cves/2026/33xxx/CVE-2026-33943.json"
    },
    {
      "type": "FIX",
      "url": "https://github.com/capricorn86/happy-dom/commit/5437fdf8f13adb9590f9f52616d9f69c3ee8db3c"
    },
    {
      "type": "WEB",
      "url": "https://github.com/capricorn86/happy-dom/releases/tag/v20.8.8"
    },
    {
      "type": "ADVISORY",
      "url": "https://github.com/capricorn86/happy-dom/security/advisories/GHSA-6q6h-j7hj-3r64"
    },
    {
      "type": "ADVISORY",
      "url": "https://nvd.nist.gov/vuln/detail/CVE-2026-33943"
    }
  ],
  "schema_version": "1.7.3",
  "severity": [
    {
      "score": "CVSS:3.1/AV:N/AC:L/PR:N/UI:R/S:U/C:H/I:H/A:H",
      "type": "CVSS_V3"
    }
  ],
  "summary": "Happy DOM ECMAScriptModuleCompiler: unsanitized export names are interpolated as executable code"
}