CVE-2025-64102: Zitadel allows brute-forcing authentication factors

Severity: critical (CVSS 9.8 v3.1)
Exploited in the wild: not listed in CISA KEV
EPSS: 0.4% probability of exploitation in the next 30 days
Public exploit or detection template: none known
Published: 2025-10-29 · updated 2026-10-19
Weakness: CWE-307

Description

Zitadel is open-source identity infrastructure software. Prior to 4.6.0, 3.4.3, and 2.71.18, an attacker can perform an online brute-force attack on OTP, TOTP, and passwords. While Zitadel allows preventing online brute force attacks in scenarios like TOTP, Email OTP, or passwords using a lockout mechanism. The mechanism is not enabled by default and can cause a denial of service for the corresponding user if enabled. Additionally, the mitigation strategies were not fully implemented in the more recent resource-based APIs. This vulnerability is fixed in 4.6.0, 3.4.3, and 2.71.18.

Affected products

zitadel: before 2.71.18; from 3.0.0 before 3.4.3; from 4.0.0 before 4.6.0 — fixed in 2.71.18, 3.4.3, 4.6.0

How to fix

Upgrade to a fixed version: zitadel 2.71.18, 3.4.3, 4.6.0. Check the vendor advisory for mitigations.

References

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