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

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: 2026-01-15 Last update: 2026-01-20 Assigner: [email protected] Source: [email protected]
NVD Status：Analyzed，CVE State: published
View at NVD, CVE.org, EUVD

CVE-2026-23511 is rated Low Risk (22.9/100): CVSS Medium severity, with low exploitation likelihood (EPSS 0.02%). Monitor for updates and reassess as exploit intelligence or EPSS changes.

Risk is dynamic; we continuously reassess and refresh what is shown on this page as upstream context changes.

Exploit prediction scoring system (EPSS) score for CVE-2026-23511

EPSS lead: Daily EPSS estimates relative likelihood of exploitation; percentile ranks this CVE among scored vulnerabilities (higher = more severe relative rank).

# Date Old EPSS score New EPSS score Delta (New - Old)
1 2026-02-18 0.05% 0.02% -0.03%
2 2026-01-21 0.04% 0.05% +0.01%
3 2026-01-16 — 0.04% —

Full EPSS history (3 records total)

Common vulnerability scoring system (CVSS) metrics for CVE-2026-23511

CVSS metrics for this CVE.

Base score Version Severity Vector Exploitability Impact Score source
5.3 3.1 MEDIUM
CVSS:3.1/AV:N/AC:L/PR:N/UI:N/S:U/C:L/I:N/A:N Click to expand
Attack vector (AV:N)
Could be attacked over the internet or any normal routed network—not just someone sitting at the machine.
Attack complexity (AC:L)
Once they can reach the bug, pulling it off is straightforward—no weird race conditions or rare setup.
Privileges required (PR:N)
No account or special rights needed—anonymous or random user is enough.
User interaction (UI:N)
Nobody has to click “OK” or open a trap file; it can work without a victim helping.
Scope (S:U)
Damage stays in the same “trust bubble” as the broken component—no big spill into unrelated systems.
Confidentiality (C:L)
Some sensitive info could get out, but not a total data dump.
Integrity (I:N)
Data isn’t meaningfully altered or forged.
Availability (A:N)
Service keeps running; no real outage angle.
 3.9 1.4 [email protected]

Weakness enumeration for CVE-2026-23511

GitHub Security Advisory for CVE-2026-23511

GHSA-pvm5-9frx-264r · Severity: medium · Ecosystem: go — Zitadel has a user enumeration vulnerability in Login UIs

Affected software / configurations for CVE-2026-23511

Vendor Product Version Raw CPE
zitadel zitadel >= 2.0.0, <= 2.71.19 cpe:2.3:a:zitadel:zitadel:*:*:*:*:*:*:*:*
zitadel zitadel >= 3.0.0, < 3.4.6 cpe:2.3:a:zitadel:zitadel:*:*:*:*:*:*:*:*
zitadel zitadel >= 4.0.0, < 4.9.1 cpe:2.3:a:zitadel:zitadel:*:*:*:*:*:*:*:*

References for CVE-2026-23511

cvelogic Threat Intelligence