What’s Vulnerable › Vulnerabilities

CVE-2026-23511: ZITADEL has a user enumeration vulnerability in Login UIs

• Severity: medium (CVSS 5.3 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: 2026-01-15 · updated 2026-06-17
• Weakness: CWE-204

Description

ZITADEL is an open source identity management platform. Prior to 4.9.1 and 3.4.6, a user enumeration vulnerability has been discovered in Zitadel's login interfaces. An unauthenticated attacker can exploit this flaw to confirm the existence of valid user accounts by iterating through usernames and userIDs. This vulnerability is fixed in 4.9.1 and 3.4.6.

Affected products

• zitadel: from 2.0.0 through 2.71.19; from 3.0.0 before 3.4.6; from 4.0.0 before 4.9.1 — fixed in 3.4.6, 4.9.1

How to fix

Upgrade to a fixed version: zitadel 3.4.6, 4.9.1. Check the vendor advisory for mitigations.

References

• https://github.com/zitadel/zitadel/commit/b85ab69e4679b0268e2b0e9b4cd04e934af10dd2
• https://github.com/zitadel/zitadel/commit/c300d4cc6a2775ab17ddfe76492f24170f8b858d
• https://github.com/zitadel/zitadel/releases/tag/v3.4.6
• https://github.com/zitadel/zitadel/releases/tag/v4.9.1
• https://github.com/zitadel/zitadel/security/advisories/GHSA-pvm5-9frx-264r

Get alerted when CVE-2026-23511 or the next vulnerability affects your stack