8.7
HighCVSS 4.0 · from GoogleCloud
CVE-2026-85268
Cross-Site Scripting (XSS) in Firebase Auth Handler via Malicious Bundle ID
Identity Platform and Firebase Authentication · Cross-site scripting · CWE-79AffectedIdentity Platform and Firebase Authentication
FixUpdate to 2026-08-14 or newer
PublishedOct 30, 10:20 · GoogleCloud
ScoredOct 30 · 8.7 · GoogleCloud
Exploit code publicNone known · checked 21:18 UTC
ExploitedNone known · CISA KEV checked 22:07 UTC
What we know
No known exploitation. CISA KEV, checked 22:07 UTC.
No public exploit code known. Exploit-DB, Metasploit, Nuclei, checked 21:18 UTC.
An attacker only needs network access to the target. No login needed. CVSS: network, no privileges.
Someone has to open, click or run something first. CVSS: user interaction required.
A successful attack can read and change data and take the service down. CVSS: high impact on confidentiality, integrity and availability.
A successful attack gives full control of the affected system. CISA: technical impact total.
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.
From GoogleCloud
Affected and fixed versions
ProductAffectedFixed inIdentity Platform and Firebase Authenticationbefore 2026-08-142026-08-14
Exploit code
Exploit-DBnone knownMetasploitnone knownNucleinone known