Vulnerability · Published Oct 4, 2026 · Assigned by VulnCheck

CVE-2026-105215ZITADEL before 4.16.2 Account Pre-Hijacking via Forged External IdP Callback

Critical 9.1

In plain English

A critical-severity authentication bypass by spoofing in zitadel from zitadel. There are no confirmed reports of exploitation so far. The chance it is exploited in the next 30 days is estimated at 0.3% (higher than 28% of all known vulnerabilities).

Severity (CVSS 3.1)9.1Critical

Exploit odds (30 days)0.3%top 72.5% of all CVEs

Exploited in the wildNo reportsCISA SSVC: none

Attack toolingNoneno public tooling known

Official 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.

Affected products (as reported)

Vendor	Product	Versions
zitadel	zitadel	4.0.0 – before 4.16.2
zitadel	zitadel	0 – before 3.4.14

Weakness: CWE-290 · Vector: CVSS:3.1/AV:N/AC:L/PR:N/UI:N/S:U/C:H/I:H/A:N

References

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