{"id":"CVE-2026-85268","kind":"vulnerability","aliases":["CVE-2026-85268"],"related":[],"title":"Firebase Authentication: XSS via malicious iOS bundle ID runs JavaScript","description":"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.","summary":"Google Cloud Identity Platform and Firebase Authentication's auth handler on iOS does not safely handle a malicious iOS bundle ID, so an attacker can inject and run arbitrary JavaScript in a victim's browser. The flaw is reachable without an account, per the NVD description.","severity":"high","cvss":8.7,"epss":null,"exploited":false,"exploited_at":null,"products":[],"ecosystems":[],"tags":["firebase","google-cloud","identity-platform","ios","vendor"],"not_affected_if":["no-firebase-auth","no-ios-auth-flow"],"how_to_check":"- Check whether the app uses Firebase Authentication or Google Cloud Identity Platform with the auth handler on iOS.","fix":"- Firebase Authentication and Google Cloud Identity Platform: versions prior to 2026-08-14 are affected; move to a release at or after that date.\n- Exact fixed version: unknown","status":"open","published_at":"2026-10-30T11:17:33+00:00","first_seen_at":"2026-10-30T11:29:51+00:00","triaged_at":"2026-10-30T11:31:22+00:00","updated_at":"2026-10-30T11:31:22+00:00","category":"vendor","confidence":0.6,"triage":{"at":"2026-10-30T11:31:22Z","model":"claude-haiku-5-5","output":{"fix":"- Firebase Authentication and Google Cloud Identity Platform: versions prior to 2026-08-14 are affected; move to a release at or after that date.\n- Exact fixed version: unknown","reach":"internet","title":"Firebase Authentication: XSS via malicious iOS bundle ID runs JavaScript","impact":"medium","summary":"Google Cloud Identity Platform and Firebase Authentication's auth handler on iOS does not safely handle a malicious iOS bundle ID, so an attacker can inject and run arbitrary JavaScript in a victim's browser. The flaw is reachable without an account, per the NVD description.","audience":"businesses","category":"vendor","nicknames":[],"who_cares":["firebase","google-cloud","identity-platform","ios"],"confidence":0.6,"fix_status":"unknown","needs_auth":"no","worst_case":"attacker runs arbitrary JavaScript in victims' browsers","analyst_note":"Check the NVD entry and Google's security bulletin for the fixed version and whether user interaction is required.","how_to_check":"- Check whether the app uses Firebase Authentication or Google Cloud Identity Platform with the auth handler on iOS.\n- unknown for exact affected versions beyond the NVD note.","plain_action":"","needs_analyst":true,"not_affected_if":["no-firebase-auth","no-ios-auth-flow"],"who_is_affected":"Applications that use Firebase Authentication or Google Cloud Identity Platform on iOS with the auth handler reachable by a remote attacker who controls a bundle ID. Apps not using these services, or not using the iOS auth flow, are likely unaffected. Exact exposure conditions are unknown from the NVD description alone.","user_interaction":"unknown","needs_special_setup":"unknown","severity_if_unknown":"high"},"cost_usd":0.000735,"input_tokens":4152,"output_tokens":640,"severity_before":"high"},"analyst_status":null,"analyst_note":null,"search":"'-08':96C '-14':97C '-2026':12A,15A '-79':79C '-85268':13A,16A '2026':95C 'account':67B 'allow':100C 'arbitrari':54B,107C 'attack':49B,104C 'auth':34B 'auth/handler':83C 'authent':2A,32B,91C 'browser':60B 'bundl':7A,45B,113C 'cloud':20B,27B,86C 'cross':74C 'cross-sit':73C 'cve':11A,14A 'cwe':78C 'descript':71B 'execut':106C 'firebas':1A,17B,31B,90C 'flaw':62B 'googl':19B,26B,85C 'google-cloud':18B 'handl':41B 'handler':35B 'id':8A,46B,114C 'ident':22B,28B,87C 'identity-platform':21B 'inject':51B 'io':6A,24B,37B,44B,99C,112C 'javascript':10A,55B,108C 'malici':5A,43B,111C 'nvd':70B 'per':68B 'platform':23B,29B,88C 'prior':93C 'reachabl':64B 'remot':103C 'run':9A,53B 'safe':40B 'script':76C 'site':75C 'unauthent':102C 'use':109C 'vendor':25B 'version':92C 'via':4A 'victim':58B 'vulner':80C 'without':65B 'xss':3A,77C","nicknames":[],"mitigations":[],"who_affected":"Applications that use Firebase Authentication or Google Cloud Identity Platform on iOS with the auth handler reachable by a remote attacker who controls a bundle ID. Apps not using these services, or not using the iOS auth flow, are likely unaffected. Exact exposure conditions are unknown from the NVD description alone.","tier":"B","verified":{},"analyst_revisit_at":null,"fix_status":"unknown","audience":"businesses","plain_action":null,"first_public_at":"2026-10-30T11:17:33+00:00","kev":null,"cvss_vector":"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/E:X/CR:X/IR:X/AR:X/MAV:X/MAC:X/MAT:X/MPR:X/MUI:X/MVC:X/MVI:X/MVA:X/MSC:X/MSI:X/MSA:X/S:X/AU:X/R:X/V:X/RE:X/U:Amber","cvss_by":"f45cbf4e-4146-4068-b7e1-655ffc2c548c","poc_count":0,"sources":[{"source":"nvd","external_id":"CVE-2026-85268","url":"https://nvd.nist.gov/vuln/detail/CVE-2026-85268","severity":null,"published_at":"2026-10-30T11:17:33+00:00","modified_at":"2026-10-30T11:17:33+00:00","first_seen_at":"2026-10-30T11:29:51+00:00","fetched_at":"2026-10-30T11:29:51+00:00","note":null}],"documents":[],"notice":"Free to read at a human pace. An API with keys and an MCP server are in preparation; early access: hello@infrastack.ai"}