{
  "fix": "Firefox Developer Edition (en-US) 139.0",
  "url": "https://patchblox.com/security/fix/windows-app/mozilla.firefox.developeredition-139.0",
  "summary": "Firefox Developer Edition (en-US) 139.0, released May 18, 2025, fixes 11 CVEs in Firefox Developer Edition (en-US). None of them is reported as exploited. Patch Radar priority: High. The latest Firefox Developer Edition (en-US) is 156.0, which also fixes every one of these CVEs.",
  "platform": "windows-app",
  "type": "app-version",
  "title": "Firefox Developer Edition (en-US) 139.0",
  "released": "2025-05-18T00:00:00Z",
  "priority": "High",
  "priorityTier": 3,
  "priorityReason": "Closes CVE-2025-4918, high severity",
  "supported": true,
  "cveCount": 11,
  "exploitedCveCount": 0,
  "kevCveCount": 0,
  "ransomwareCveCount": 0,
  "maxEpss": 0.09515,
  "maxCvss": 9.8,
  "appliesTo": [
    {
      "product": "Firefox Developer Edition (en-US)",
      "productUrl": "https://patchblox.com/security/product/windows-app/firefox-developer-edition-en-us",
      "fixedVersion": "139.0",
      "latestVersion": "156.0",
      "supported": true
    }
  ],
  "supersededBy": {
    "product": "Firefox Developer Edition (en-US)",
    "latestVersion": "156.0",
    "productUrl": "https://patchblox.com/security/product/windows-app/firefox-developer-edition-en-us"
  },
  "cves": [
    {
      "cveId": "CVE-2025-4918",
      "url": "https://patchblox.com/security/cve/CVE-2025-4918",
      "title": "Out-of-bounds access when resolving Promise objects",
      "priority": "High",
      "severity": "Medium",
      "cvss": 9.8,
      "epss": 0.09515,
      "kev": false,
      "ransomware": false,
      "exploited": false,
      "disclosed": false
    },
    {
      "cveId": "CVE-2025-4919",
      "url": "https://patchblox.com/security/cve/CVE-2025-4919",
      "title": "Out-of-bounds access when optimizing linear sums",
      "priority": "High",
      "severity": "Important",
      "cvss": 8.8,
      "epss": 0.09115,
      "kev": false,
      "ransomware": false,
      "exploited": false,
      "disclosed": false
    },
    {
      "cveId": "CVE-2025-5268",
      "url": "https://patchblox.com/security/cve/CVE-2025-5268",
      "title": "Memory safety bugs fixed in Firefox 139, Thunderbird 139, Firefox ESR 128.11, and Thunderbird 128.11",
      "priority": "High",
      "severity": "Important",
      "cvss": 8.8,
      "epss": 0.0051,
      "kev": false,
      "ransomware": false,
      "exploited": false,
      "disclosed": false
    },
    {
      "cveId": "CVE-2025-5266",
      "url": "https://patchblox.com/security/cve/CVE-2025-5266",
      "title": "Script element events leaked cross-origin resource status",
      "priority": "High",
      "severity": "Important",
      "cvss": 8.8,
      "epss": 0.00341,
      "kev": false,
      "ransomware": false,
      "exploited": false,
      "disclosed": false
    },
    {
      "cveId": "CVE-2025-5272",
      "url": "https://patchblox.com/security/cve/CVE-2025-5272",
      "title": "Memory safety bugs fixed in Firefox 139 and Thunderbird 139",
      "priority": "High",
      "severity": "Medium",
      "cvss": 7.3,
      "epss": 0.0034,
      "kev": false,
      "ransomware": false,
      "exploited": false,
      "disclosed": false
    },
    {
      "cveId": "CVE-2025-5264",
      "url": "https://patchblox.com/security/cve/CVE-2025-5264",
      "title": "Potential local code execution in \u201CCopy as cURL\u201D command",
      "priority": "High",
      "severity": "Important",
      "cvss": 8.8,
      "epss": 0.00303,
      "kev": false,
      "ransomware": false,
      "exploited": false,
      "disclosed": false
    },
    {
      "cveId": "CVE-2025-5270",
      "url": "https://patchblox.com/security/cve/CVE-2025-5270",
      "title": "SNI was sometimes unencrypted",
      "priority": "High",
      "severity": "Medium",
      "cvss": 7.5,
      "epss": 0.00285,
      "kev": false,
      "ransomware": false,
      "exploited": false,
      "disclosed": false
    },
    {
      "cveId": "CVE-2025-5267",
      "url": "https://patchblox.com/security/cve/CVE-2025-5267",
      "title": "Clickjacking vulnerability could have led to leaking saved payment card details",
      "priority": "High",
      "severity": "Important",
      "cvss": 8.8,
      "epss": 0.00281,
      "kev": false,
      "ransomware": false,
      "exploited": false,
      "disclosed": false
    },
    {
      "cveId": "CVE-2025-5263",
      "url": "https://patchblox.com/security/cve/CVE-2025-5263",
      "title": "Error handling for script execution was incorrectly isolated from web content",
      "priority": "High",
      "severity": "Medium",
      "cvss": 8.8,
      "epss": 0.00265,
      "kev": false,
      "ransomware": false,
      "exploited": false,
      "disclosed": false
    },
    {
      "cveId": "CVE-2025-5271",
      "url": "https://patchblox.com/security/cve/CVE-2025-5271",
      "title": "Devtools\u0027 preview ignored CSP headers",
      "priority": "Routine",
      "severity": "Medium",
      "cvss": 6.5,
      "epss": 0.00304,
      "kev": false,
      "ransomware": false,
      "exploited": false,
      "disclosed": false
    },
    {
      "cveId": "CVE-2025-5265",
      "url": "https://patchblox.com/security/cve/CVE-2025-5265",
      "title": "Potential local code execution in \u201CCopy as cURL\u201D command",
      "priority": "Routine",
      "severity": "Medium",
      "cvss": 4.8,
      "epss": 0.00208,
      "kev": false,
      "ransomware": false,
      "exploited": false,
      "disclosed": false
    }
  ],
  "dataAsOf": "2026-11-08T13:06:02Z",
  "attribution": {
    "text": "Data: Patchblox Patch Radar",
    "url": "https://patchblox.com/security/patch-radar",
    "terms": "https://patchblox.com/security/patch-radar/use-the-data"
  }
}