{
    "dataType": "CVE_RECORD",
    "dataVersion": "5.2",
    "cveMetadata": {
        "cveId": "CVE-2026-85268",
        "assignerOrgId": "f45cbf4e-4146-4068-b7e1-655ffc2c548c",
        "state": "PUBLISHED",
        "assignerShortName": "GoogleCloud",
        "dateReserved": "2026-09-03T16:36:41.159Z",
        "datePublished": "2026-10-30T10:20:06.249Z",
        "dateUpdated": "2026-10-30T10:20:06.249Z"
    },
    "containers": {
        "cna": {
            "providerMetadata": {
                "orgId": "f45cbf4e-4146-4068-b7e1-655ffc2c548c",
                "shortName": "GoogleCloud",
                "dateUpdated": "2026-10-30T10:20:06.249Z"
            },
            "title": "Cross-Site Scripting (XSS) in Firebase Auth Handler via Malicious Bundle ID",
            "problemTypes": [
                {
                    "descriptions": [
                        {
                            "lang": "en",
                            "cweId": "CWE-79",
                            "description": "CWE-79 Improper Neutralization of Input During Web Page Generation (XSS or 'Cross-site Scripting')",
                            "type": "CWE"
                        }
                    ]
                }
            ],
            "impacts": [
                {
                    "capecId": "CAPEC-63",
                    "descriptions": [
                        {
                            "lang": "en",
                            "value": "CAPEC-63 Cross-Site Scripting (XSS)"
                        }
                    ]
                }
            ],
            "affected": [
                {
                    "vendor": "Google Cloud",
                    "product": "Identity Platform and Firebase Authentication",
                    "platforms": [
                        "iOS"
                    ],
                    "versions": [
                        {
                            "status": "affected",
                            "version": "0",
                            "lessThan": "2026-08-14",
                            "versionType": "date"
                        }
                    ],
                    "defaultStatus": "unaffected"
                }
            ],
            "descriptions": [
                {
                    "lang": "en",
                    "value": "A Cross-Site Scripting (XSS) (CWE-79) vulnerability in the auth/handler in Google Cloud Identity Platform and Firebase Authentication versions prior to 2026-08-14 on iOS allows an unauthenticated remote attacker to execute arbitrary JavaScript using a malicious iOS bundle ID.",
                    "supportingMedia": [
                        {
                            "type": "text/html",
                            "base64": false,
                            "value": "<p>A Cross-Site Scripting (XSS) (CWE-79) vulnerability in the auth/handler in Google Cloud Identity Platform and Firebase Authentication versions prior to 2026-08-14 on iOS allows an unauthenticated remote attacker to execute arbitrary JavaScript using a malicious iOS bundle ID.</p>"
                        }
                    ]
                }
            ],
            "references": [
                {
                    "url": "https://firebase.google.com/support/releases#auth-helper-fix"
                }
            ],
            "metrics": [
                {
                    "format": "CVSS",
                    "scenarios": [
                        {
                            "lang": "en",
                            "value": "GENERAL"
                        }
                    ],
                    "cvssV4_0": {
                        "attackVector": "NETWORK",
                        "attackComplexity": "LOW",
                        "attackRequirements": "NONE",
                        "privilegesRequired": "NONE",
                        "userInteraction": "PASSIVE",
                        "vulnConfidentialityImpact": "HIGH",
                        "subConfidentialityImpact": "LOW",
                        "vulnIntegrityImpact": "HIGH",
                        "subIntegrityImpact": "LOW",
                        "vulnAvailabilityImpact": "HIGH",
                        "subAvailabilityImpact": "LOW",
                        "exploitMaturity": "NOT_DEFINED",
                        "Safety": "NOT_DEFINED",
                        "Automatable": "NOT_DEFINED",
                        "Recovery": "NOT_DEFINED",
                        "valueDensity": "NOT_DEFINED",
                        "vulnerabilityResponseEffort": "NOT_DEFINED",
                        "providerUrgency": "AMBER",
                        "version": "4.0",
                        "baseSeverity": "HIGH",
                        "baseScore": 8.7,
                        "vectorString": "CVSS:4.0/AV:N/AC:L/AT:N/PR:N/UI:P/VC:H/VI:H/VA:H/SC:L/SI:L/SA:L/U:Amber"
                    }
                }
            ],
            "solutions": [
                {
                    "lang": "en",
                    "value": "This vulnerability has been patched for all users and no app updates are required. Action is only needed for developers who followed Option 4 (self-hosting the helper code) in the Firebase redirect best practices documentation https://firebase.google.com/docs/auth/web/redirect-best-practices#self-host-helper-code. These users should re-synchronize the helper code to make sure they are hosting the latest version.",
                    "supportingMedia": [
                        {
                            "type": "text/html",
                            "base64": false,
                            "value": "This vulnerability has been patched for all users and no app updates are required. Action is only needed for developers who followed Option 4 (self-hosting the helper code) in the <a href=\"https://firebase.google.com/docs/auth/web/redirect-best-practices#self-host-helper-code\">Firebase redirect best practices documentation</a>. These users should re-synchronize the helper code to make sure they are hosting the latest version."
                        }
                    ]
                }
            ],
            "credits": [
                {
                    "lang": "en",
                    "value": "Mathias Karlsson",
                    "type": "reporter"
                }
            ],
            "source": {
                "discovery": "EXTERNAL"
            },
            "x_generator": {
                "engine": "Vulnogram 1.0.2"
            }
        }
    }
}