{"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":"2026-10-30T16:48:22.519Z"},"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"}},"adp":[{"metrics":[{"other":{"type":"ssvc","content":{"timestamp":"2026-10-30T16:48:10.216800Z","id":"CVE-2026-85268","options":[{"Exploitation":"none"},{"Automatable":"no"},{"Technical Impact":"total"}],"role":"CISA Coordinator","version":"2.0.3"}}}],"title":"CISA ADP Vulnrichment","providerMetadata":{"orgId":"134c704f-9b21-4f2e-91b3-4a467353bcc0","shortName":"CISA-ADP","dateUpdated":"2026-10-30T16:48:22.519Z"}}]}}