Auth bypass in Zitadel
CVE-2025-64103
Starting from 2.53.6, 2.54.3, and 2.55.0, Zitadel only required multi factor authentication in case the login policy has either enabled requireMFA or requireMFAForLocalUsers. If a user has set up MFA without this requirement, Zitadel would consider single factor auhtenticated sessions as valid as well and not require multiple factors. Bypassing second authentication factors weakens multifactor authentication and enables attackers to bypass the more secure factor. An attacker can target the TOTP code alone, only six digits, bypassing password verification entirely and potentially compromising accounts with 2FA enabled. This vulnerability is fixed in 4.6.0, 3.4.3, and 2.71.18.
Vulnerability class: Broken Authentication
EPSS: 0.003 (25.8th percentile) — read the EPSS interpretation.
CVSS v3 metric
CVSS v3 base score 9.8 (Critical). Vector: CVSS:3.1/AV:N/AC:L/PR:N/UI:N/S:U/C:H/I:H/A:H.
Affected products
- Zitadel — versions >= 4.0.0-rc.1, < 4.6.0, >= 3.0.0-rc.1, < 3.4.3, >= 2.55.0, < 2.71.18
Weakness classification (CWE)
References
- security-advisories@github.com (x_refsource_CONFIRM, Vendor Advisory)
- security-advisories@github.com (Patch, x_refsource_MISC)
Frequently asked questions
- What is CVE-2025-64103?
- CVE-2025-64103 is a critical-severity vulnerability in Zitadel, classified under Improper Authentication. CVSS score: 9.8/10. Published 2025-10-29.
- How severe is CVE-2025-64103?
- Critical severity. CVSS v3 base score is 9.8 out of 10.