CVE-2026-109371
ZITADEL 3.0.0 before 4.18.0 Unauthenticated Username Change via Login V1
- State
- Published
- Severity
- 8.8 High
- Published
- Oct 12, 2026
- Updated
- Oct 15, 2026
- Reserved
- Oct 12, 2026
Description
ZITADEL 3.0.0 before 4.18.0 contains a missing authentication vulnerability in the hosted Login V1 UI, where the change-username handler acts on the account bound to a login flow before any factor is verified. Unauthenticated attackers can submit a victim's login name and then post a new username to rename any active human user, including administrators, locking them out.
Scores
| CVSS | Score | Vector | Source |
|---|---|---|---|
| 4.0 | 8.8 High | CVSS:4.0/AV:N/AC:L/AT:N/PR:N/UI:N/VC:N/VI:H/VA:L/SC:N/SI:N/SA:N | VulnCheck |
| 3.1 | 8.2 High | CVSS:3.1/AV:N/AC:L/PR:N/UI:N/S:U/C:N/I:H/A:L | VulnCheck |
Weaknesses
- CWE-306 Missing Authentication for Critical Function
Affected Products
| Product | Versions |
|---|---|
zitadelzitadel |
|
References
- GitHub Security Advisory (GHSA-4hgj-wm6c-q7p2)vendor-advisory
- VulnCheck Advisory: ZITADEL 3.0.0 before 4.18.0 Unauthenticated Username Change via Login V1third-party-advisory
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