- Critical 9.2
CVE-2026-105211
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.
Scores
The facts
- Published
- 4 October 2026
- Last changed
- 5 October 2026
- NVD status
- Deferred
- Severity
- Critical, CVSS 9.2 out of 10 (version 4.0)
CVSS:4.0/AV:N/AC:H/AT:P/PR:N/UI:N/VC:H/VI:H/VA:H/SC:N/SI:N/SA:N/E:X/CR:X/IR:X/AR:X/MAV:X/MAC:X/MAT:X/MPR:X/MUI:X/MVC:X/MVI:X/MVA:X/MSC:X/MSI:X/MSA:X/S:X/AU:X/R… - Weakness
- Known exploited
- Not in the CISA Known Exploited Vulnerabilities catalogue in this build.
- EPSS
- 0.3% chance of exploitation activity in the next 30 days (percentile 25).
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