A vulnerability in the EnableTwoFactorAuthRequest SOAP endpoint of Zimbra Collaboration (ZCS) allows an attacker with valid user credentials to bypass Two-Factor Authentication (2FA) protection. The attacker can configure an additional 2FA method (either a third-party authenticator app or email-based 2FA) without presenting a valid authentication token or proving access to an already configured 2FA method. This bypasses 2FA and results in unauthorized access to accounts that are otherwise protected by 2FA.
Conclusion & alert: CVE-2025-54391 is rated Moderate Risk (43.5/100): CVSS Critical severity, with low exploitation likelihood (EPSS 0.06%). Mandatory action: Review affected assets and schedule remediation.
Risk is dynamic; we continuously reassess and refresh what is shown on this page as upstream context changes.
EPSS lead: Daily EPSS estimates relative likelihood of exploitation; percentile ranks this CVE among scored vulnerabilities (higher = more severe relative rank).
| # | Date | Old EPSS score | New EPSS score | Delta (New - Old) |
|---|---|---|---|---|
| 1 | 2025-09-18 | 0.04% | 0.06% | +0.02% |
| 2 | 2025-09-17 | — | 0.04% | — |
Full EPSS history (2 records total)
CVSS metrics for this CVE.
| Base score | Version | Severity | Vector | Exploitability | Impact | Score source |
|---|---|---|---|---|---|---|
| 9.1 | 3.1 | CRITICAL |
|
3.9 | 5.2 | 134c704f-9b21-4f2e-91b3-4a467353bcc0 |
| Vendor | Product | Version | Raw CPE |
|---|---|---|---|
| No affected products in dataset. | |||