CVE-2026-105215

critical

Description

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.

References

https://www.vulncheck.com/advisories/zitadel-before-4.16.2-account-pre-hijacking-via-forged-external-idp-callback

https://github.com/zitadel/zitadel/security/advisories/GHSA-738m-7888-jfv8

https://euvd.enisa.europa.eu/vulnerability/EUVD-2026-92108

Details

Source: Mitre, NVD

Published: 2026-10-04

Updated: 2026-10-04

Risk Information

CVSS v2

Base Score: 9.4

Vector: CVSS2#AV:N/AC:L/Au:N/C:C/I:C/A:N

Severity: High

CVSS v3

Base Score: 9.1

Vector: CVSS:3.1/AV:N/AC:L/PR:N/UI:N/S:U/C:H/I:H/A:N

Severity: Critical

CVSS v4

Base Score: 9.3

Vector: CVSS:4.0/AV:N/AC:L/AT:N/PR:N/UI:N/VC:H/VI:H/VA:N/SC:N/SI:N/SA:N

Severity: Critical