Medium severity · published Jan 15, 2026
CVE-2026-23511
ZITADEL has a user enumeration vulnerability in Login UIs
5.3
CVSS
0.4%
EPSS
No
On KEV
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.
CVSS vector
CVSS:3.1/AV:N/AC:L/PR:N/UI:N/S:U/C:L/I:N/A:N
Attack vector
Network
Complexity
Low
Privileges
None
User interaction
None
Confidentiality
Low
Integrity
None
Availability
None
Scope
Unchanged
Exploitation
Is it being used?
Exploit prediction (EPSS)0.4% · higher than 34% of CVEs
Exploited in the wildNo evidence yet
CISA KEVNot listed
Ransomware campaign useNot known
Affected products
Which versions
ZI
zitadel · zitadel
>= 4.0.0, < 4.9.1; < 3.4.6 · source: vendor, NVD
References
NVD
https://nvd.nist.gov/vuln/detail/CVE-2026-23511
CVE.org
https://www.cve.org/CVERecord?id=CVE-2026-23511
Patch
https://github.com/zitadel/zitadel/commit/b85ab69e4679b0268e2b0e9b4cd04e934af10dd2
Patch
https://github.com/zitadel/zitadel/commit/c300d4cc6a2775ab17ddfe76492f24170f8b858d
Release Notes
https://github.com/zitadel/zitadel/releases/tag/v3.4.6
Release Notes
https://github.com/zitadel/zitadel/releases/tag/v4.9.1
Third Party Advisory
https://github.com/zitadel/zitadel/security/advisories/GHSA-pvm5-9frx-264r
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