All vulnerabilities
CVE-2026-105211GHSA-3gwm-5wx8-4gm6

ZITADEL before 4.17.1 Authentication Bypass via Login V2 OTP returnCode

zitadel zitadel
Open in ThreatlineRecord JSON
CVSS
9.2Critical
ExploitationNo known exploitationNot in CISA KEV, which does not prove it is unexploitedCISA KEV
Exploit odds (EPSS)0.33%Chance of exploitation activity in the next 30 days, higher than 25% of CVEs. Scored 23 Oct 2026FIRST EPSS
Fixed in4.17.1Fixed versionCVE List
Published4 Oct 2026Updated 5 Oct 2026CVE List

What fixes it

A fixed version on one release line is not the upgrade target for every line. Check your exact version and any vendor backports.

Description

ZITADEL before 4.17.1 contains an authentication bypass vulnerability in Login V2 that allows unauthenticated attackers to take over accounts by obtaining OTP codes via the returnCode delivery type. Attackers knowing a login name of a victim with OTP-Email and OTP-SMS enrolled can read both codes from server-action responses to gain MFA-authenticated sessions, including administrator takeover.

Text from CVE List

Affected versions 2

  • zitadelaffected: all versions before 4.17.1CVE List
  • zitadelunaffected: 4.17.1CVE List

References 2