# CVE-2026-85268: Cross-Site Scripting (XSS) in Firebase Auth Handler via Malicious Bundle ID

> CVE-2026-85268: Cross-Site Scripting (XSS) in Firebase Auth Handler via Malicious Bundle ID. CVSS 8.7 (CVSS 4.0).

Canonical: https://rewindex.com/cve/CVE-2026-85268
Last updated: 2026-10-30T19:37:07Z

- Published: 2026-10-30 10:20 UTC · Updated: 2026-10-30 19:37 UTC · Assigner: GoogleCloud
- CVSS: 8.7 (CVSS 4.0) · Severity: High
- EPSS: 0.58%, 48th percentile (scored 2026-11-04)
- CISA KEV: no
- CWE: CWE-79

## 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.

## Affected vendors and products

- Google Cloud: Identity Platform and Firebase Authentication

## Tracked companies

- [Google Cloud](https://rewindex.com/company/google-cloud.md)

## References

- [CVE record on cve.org](https://www.cve.org/CVERecord?id=CVE-2026-85268)
- [NVD entry](https://nvd.nist.gov/vuln/detail/CVE-2026-85268)
- [https://firebase.google.com/support/releases\#auth-helper-fix](https://firebase.google.com/support/releases#auth-helper-fix)

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_Sources: CVE records from the CVE Program (cve.org). CVE® is a registered trademark of The MITRE Corporation. (https://www.cve.org/) This product uses data from the NVD API but is not endorsed or certified by the NVD. (https://nvd.nist.gov/) Known Exploited Vulnerabilities catalog from CISA. (https://www.cisa.gov/known-exploited-vulnerabilities-catalog) EPSS scores from FIRST (Exploit Prediction Scoring System). (https://www.first.org/epss/)_


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Canonical: https://rewindex.com/cve/CVE-2026-85268 · Markdown: https://rewindex.com/cve/CVE-2026-85268.md · JSON: https://rewindex.com/api/v1/cves/CVE-2026-85268 · Data licensed CC BY 4.0 (https://creativecommons.org/licenses/by/4.0/) · Generated 2026-11-05T14:06:16.880Z