CVE-2026-105215

ZITADEL before 4.16.2 Account Pre-Hijacking via Forged External IdP Callback

State: Published
Severity: 9.3 Critical
Published: Oct 4, 2026
Updated: Oct 29, 2026
Reserved: Oct 4, 2026

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.

Scores

CVSS	Score	Vector	Source
4.0	9.3 Critical	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	VulnCheck
3.1	9.1 Critical	CVSS:3.1/AV:N/AC:L/PR:N/UI:N/S:U/C:H/I:H/A:N	VulnCheck

Weaknesses

CWE-290 Authentication Bypass by Spoofing

Affected Products

Product	Versions
zitadelzitadel	4.0.0 to before 4.16.2Affected 4.16.2Not affected
zitadelzitadel	before 3.4.14Affected 3.4.14Not affected

References

GitHub Security Advisory (GHSA-738m-7888-jfv8)vendor-advisory
VulnCheck Advisory: ZITADEL before 4.16.2 Account Pre-Hijacking via Forged External IdP Callbackthird-party-advisory

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