{
  "affected": [
    {
      "ranges": [
        {
          "database_specific": {
            "extracted_events": [
              {
                "range": [
                  {
                    "introduced": "0"
                  },
                  {
                    "fixed": "20.14.6"
                  }
                ],
                "source": "AFFECTED_FIELD",
                "strategy": "StringRangeExpression"
              },
              {
                "range": [
                  {
                    "fixed": "f21dbd7d0a0c63cdd41954ba5d0f05def4e0f2b3"
                  }
                ],
                "source": "REFERENCES_COMMIT"
              },
              {
                "original_tag": "v20.14.6",
                "range": [
                  {
                    "fixed": "f21dbd7d0a0c63cdd41954ba5d0f05def4e0f2b3"
                  }
                ],
                "source": "REFERENCES_TAG"
              },
              {
                "range": [
                  {
                    "introduced": "0"
                  },
                  {
                    "fixed": "20.14.6"
                  }
                ],
                "source": "DESCRIPTION"
              }
            ]
          },
          "events": [
            {
              "introduced": "0"
            },
            {
              "fixed": "f21dbd7d0a0c63cdd41954ba5d0f05def4e0f2b3"
            }
          ],
          "repo": "https://github.com/capricorn86/happy-dom",
          "type": "GIT"
        }
      ]
    }
  ],
  "aliases": [
    "GHSA-5fpq-26gf-qwcr"
  ],
  "database_specific": {
    "cna_assigner": "GitHub_M",
    "cwe_ids": [
      "CWE-565"
    ],
    "osv_generated_from": "https://github.com/CVEProject/cvelistV5/tree/main/cves/2026/118xxx/CVE-2026-118661.json"
  },
  "details": "Happy DOM is a JavaScript implementation of a web browser without its graphical user interface. Prior to 20.14.6, Happy DOM's CookieContainer in src/cookie/CookieContainer.ts does not correctly validate or match Domain cookie attributes. It can accept a Domain unrelated to the origin setting the cookie, including a public suffix, and separately treats an unrelated suffix-sharing hostname as a match because cookieMatchesURL does not enforce a DNS-label boundary. In server-side rendering and prerendering applications that contact attacker-controlled origins and then make requests to a victim origin, these behaviors can plant and deliver a forged cookie, enabling cookie injection or session fixation. This issue is fixed in version 20.14.6.",
  "id": "CVE-2026-118661",
  "modified": "2026-10-30T02:30:27.685830846Z",
  "published": "2026-10-28T20:30:23.868Z",
  "references": [
    {
      "type": "WEB",
      "url": "https://github.com/capricorn86/happy-dom/releases/tag/v20.14.6"
    },
    {
      "type": "ADVISORY",
      "url": "https://github.com/CVEProject/cvelistV5/tree/main/cves/2026/118xxx/CVE-2026-118661.json"
    },
    {
      "type": "ADVISORY",
      "url": "https://github.com/capricorn86/happy-dom/security/advisories/GHSA-5fpq-26gf-qwcr"
    },
    {
      "type": "ADVISORY",
      "url": "https://nvd.nist.gov/vuln/detail/CVE-2026-118661"
    },
    {
      "type": "FIX",
      "url": "https://github.com/capricorn86/happy-dom/commit/f21dbd7d0a0c63cdd41954ba5d0f05def4e0f2b3"
    },
    {
      "type": "FIX",
      "url": "https://github.com/capricorn86/happy-dom/pull/2477"
    }
  ],
  "schema_version": "1.9.2",
  "severity": [
    {
      "score": "CVSS:3.1/AV:N/AC:L/PR:N/UI:N/S:U/C:L/I:L/A:N",
      "type": "CVSS_V3"
    }
  ],
  "summary": "Happy DOM: Cookie scope forgery: no DNS-label boundary on Domain= matching , attacker origin sets victim cookies"
}