What is CVE-2026-105215?

CVE-2026-105215 is a critical-severity vulnerability in Zitadel, classified under Authentication Bypass by Spoofing. CVSS score: 9.1/10. Published 2026-10-04.

How severe is CVE-2026-105215?

Critical severity. CVSS v3 base score is 9.1 out of 10.

Vulnerability in Zitadel

CVE-2026-105215

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.

Published 2026-10-04 · last modified 2026-10-04.

CVSS v3 metric

CVSS v3 base score 9.1 (Critical). Vector: CVSS:3.1/AV:N/AC:L/PR:N/UI:N/S:U/C:H/I:H/A:N.

EPSS exploit prediction

No EPSS score from FIRST.org yet. New CVEs usually get one within a few days; no score means no signal yet, not low risk. How EPSS works.

Affected products

Zitadel

Weakness classification (CWE)

CWE-290 — Authentication Bypass by Spoofing

References

github.com/zitadel/zitadel/security/advisories/GHSA-738m-7888-jfv8 (vendor-advisory)
www.vulncheck.com/advisories/zitadel-before-4.16.2-account-pre-hijacking-via-fo… (third-party-advisory)

Frequently asked questions

What is CVE-2026-105215?: CVE-2026-105215 is a critical-severity vulnerability in Zitadel, classified under Authentication Bypass by Spoofing. CVSS score: 9.1/10. Published 2026-10-04.
How severe is CVE-2026-105215?: Critical severity. CVSS v3 base score is 9.1 out of 10.