{
  "affected": [
    {
      "ranges": [
        {
          "database_specific": {
            "cpe": "cpe:2.3:a:mozilla:firefox_mobile:*:*:*:*:*:iphone_os:*:*",
            "extracted_events": [
              {
                "introduced": "0"
              },
              {
                "fixed": "152.0"
              }
            ],
            "source": "CPE_RANGE"
          },
          "events": [
            {
              "introduced": "0"
            },
            {
              "fixed": "df0ceea8ef301835448e61fb2ed08a8bd30f8bbf"
            }
          ],
          "repo": "https://github.com/mozilla-mobile/firefox-ios",
          "type": "GIT"
        }
      ]
    }
  ],
  "database_specific": {
    "cna_assigner": "mozilla",
    "osv_generated_from": "https://github.com/CVEProject/cvelistV5/tree/main/cves/2026/53xxx/CVE-2026-53899.json"
  },
  "details": "Firefox for iOS used partial domain matching when attaching cookies to PDF requests, allowing a malicious site on a suffix domain to receive cookies belonging to the target site. This vulnerability was fixed in Firefox for iOS 152.0.",
  "id": "CVE-2026-53899",
  "modified": "2026-08-21T11:30:12.433907248Z",
  "published": "2026-06-16T11:53:04.805Z",
  "references": [
    {
      "type": "ADVISORY",
      "url": "https://github.com/CVEProject/cvelistV5/tree/main/cves/2026/53xxx/CVE-2026-53899.json"
    },
    {
      "type": "ADVISORY",
      "url": "https://nvd.nist.gov/vuln/detail/CVE-2026-53899"
    },
    {
      "type": "ADVISORY",
      "url": "https://www.mozilla.org/security/advisories/mfsa2026-56/"
    },
    {
      "type": "REPORT",
      "url": "https://bugzilla.mozilla.org/show_bug.cgi?id=2042909"
    }
  ],
  "schema_version": "1.9.0",
  "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": "Cross-origin cookies could be leaked when opening a PDF link"
}