---
id: CVE-2026-105215
title: >-
  ZITADEL before 3.4.14 and 4.x before 4.16.2 contains an authentication bypass
  in the hosted Login V1 UI because the 'external account not found'
  registration endpoint trusts client-supplied external identity fields without
  a completed Id…
summary: >-
  ZITADEL before 3.4.14 and 4.x before 4.16.2 contains an authentication bypass
  in the hosted Login V1 UI because the 'external account not found'
  registration endpoint trusts client-supplied external identity fields without
  a completed Id…
severity: critical
cvss: 9.1
cvssVector: 'CVSS:3.1/AV:N/AC:L/PR:N/UI:N/S:U/C:H/I:H/A:N'
cwe:
  - CWE-290
vendor: zitadel
product: zitadel
affected:
  - zitadel < 4.16.2
  - zitadel < 3.4.14
published: '2026-10-04'
updated: '2026-10-04'
sourceUpdated: '2026-10-04T15:16:33.107'
source: NVD
sourceUrl: 'https://nvd.nist.gov/vuln/detail/CVE-2026-105215'
references:
  - url: 'https://github.com/zitadel/zitadel/security/advisories/GHSA-738m-7888-jfv8'
    label: disclosure@vulncheck.com
  - url: >-
      https://www.vulncheck.com/advisories/zitadel-before-4.16.2-account-pre-hijacking-via-forged-external-idp-callback
    label: disclosure@vulncheck.com
tags:
  - nvd
  - cve.org
ingestedAt: '2026-10-04T15:00:34.388Z'
---

## Overview

ZITADEL before 3.4.14 and 4.x before 4.16.2 contains an authentication bypass in the hosted Login V1 UI because the 'external account not found' registration endpoint trusts client-supplied external identity fields without a completed IdP callback. Unauthenticated attackers can submit forged IDPConfigID and ExternalUserID values to pre-create an account bound to a victim's external IdP identity, which the victim's later genuine external login then signs into.

## Remediation

Refer to the linked advisories for vendor-supplied fixes and affected version ranges.