Vulnerability in Zitadel

CVE-2026-23511

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.

Published · last modified .

CVSS v3 metric

CVSS v3 base score 5.3 (Medium). Vector: CVSS:3.1/AV:N/AC:L/PR:N/UI:N/S:U/C:L/I:N/A:N.

EPSS exploit prediction

EPSS: 0.004 (32.5th percentile), scored .

Very low probability of exploitation in the next 30 days; routine patching cadence is appropriate. 32nd percentile — 32.5% of CVEs in the catalogue have a lower EPSS than this one. How to read EPSS.

EPSS trend (30 days)EPSS over the last 30 days for CVE-2026-23511: held from 0.004 to 0.004.

EPSS over last 30 days · oldest: 0.004 · newest: 0.004 · change: +0.000

Affected products

  • Zitadel — versions >= 4.0.0, < 4.9.1, < 3.4.6

Weakness classification (CWE)

References

Frequently asked questions

What is CVE-2026-23511?
CVE-2026-23511 is a medium-severity vulnerability in Zitadel, classified under Observable Response Discrepancy. CVSS score: 5.3/10. Published 2026-01-15.
How severe is CVE-2026-23511?
Medium severity. CVSS v3 base score is 5.3 out of 10.