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MEDIUM

ZITADEL user enumeration vulnerability in login UI

Published Aug 22, 2025

Description

The open-source identity infrastructure software Zitadel allows administrators to disable the user self-registration. Versions 4.0.0 to 4.0.2, 3.0.0 to 3.3.6, and all versions prior to 2.71.15 are vulnerable to a username enumeration issue in the login interface. The login UI includes a security feature, Ignoring unknown usernames, that is intended to prevent username enumeration by returning a generic response for both valid and invalid usernames. This vulnerability allows an unauthenticated attacker to bypass this protection by submitting arbitrary userIDs to the select account page and distinguishing between valid and invalid accounts based on the system's response. For effective exploitation, an attacker needs to iterate through possible userIDs, but the impact can be limited by implementing rate limiting or similar measures. The issue has been patched in versions 4.0.3, 3.4.0, and 2.71.15.

Affected products

Remediation

No remediation recorded yet.

Metrics

Weaknesses (1)

References (6)

Change history (0)

No recorded changes yet.

Sources
CVE.org / MITRE
Status PUBLISHED
Assigner GitHub_M
Published Aug 22, 2025
Updated Aug 22, 2025
Reserved Aug 19, 2025
CISA Vulnrichment
Updated Aug 22, 2025
NVD
Status Analyzed
Modified Jun 17, 2026
Red Hat
Severity n/a
Public date n/a