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

What is CVE-2026-23511?

CVE-2026-23511 is a medium-severity vulnerability in zitadel, published on 15 Jan 2026. An attacker can exploit it over the internet without logging in, with no action from the victim.

Official 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.

Weakness: CWE-204

Which versions are affected by CVE-2026-23511?

5 open source packages ship an affected version, including github.com/zitadel/zitadel. It affects 1 product.

Products include Zitadel Zitadel.

How do I fix CVE-2026-23511?

Upgrade github.com/zitadel/zitadel to a fixed version for your release line: 3.4.6 or 4.9.1.

Is CVE-2026-23511 being exploited?

There is no known exploitation of CVE-2026-23511 in the wild and no public exploit code.

Other vulnerabilities in zitadel

• CVE-2026-29191 ZITADEL: 1-Click Account Takeover via XSS in /saml-post Endpoint Critical 9.3
• CVE-2025-67494 ZITADEL Vulnerable to Unauthenticated Full-Read SSRF via V2 Login Critical 9.3
• CVE-2025-27507 IDOR Vulnerabilities in ZITADEL's Admin API that Primarily Impact LDAP Configurations Critical 9.0
• CVE-2025-64103 Zitadel Bypass Second Authentication Factor High 8.7
• CVE-2025-31123 Zitadel Expired JWT Keys Usable for Authorization Grants High 8.7

Sources

• CVE record
• NVD
• OSV
• GitHub advisory
• How this page is made

Also known as GHSA-pvm5-9frx-264r, GO-2026-4319.