by Kastro
Paper/Archive/CVE-2026-105215

CVE-2026-105215

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

EPSS 0.3%CVSS 9.3
critical.is priorityof 100
33
CVSS 9.3 (CNA)9.3 / 10 × 3027.9Not in CISA KEV+300.0EPSS percentile 27.4.274 × 205.5No public exploit+100.0SSVC exploitation: none+100.0
Description · from the CVE record

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

ProductAffectedFixed inSource
zitadel4.0.0 – < 4.16.24.16.2CNA
zitadel< 3.4.143.4.14CNA

Scores by source

VulnCheck (CNA)9.3CVSS: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 (CNA)9.1CVSS:3.1/AV:N/AC:L/PR:N/UI:N/S:U/C:H/I:H/A:N
CISA ADPSSVCExploitation: none · Automatable: yes · Technical impact: total

References

advisorygithub.com/zitadel/zitadel/security/advisories/GHSA-738m-7888-jfv8writeupvulncheck.com/advisories/zitadel-before-4.16.2-account-pre-hijacking-via-forged-external-idp-callback