CVE-2026-109371

HIGHCVSS 8.2

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.

Timeline

Published:October 12th, 2026 5:17 PM

Last modified:October 15th, 2026 3:17 AM

CVSS Scoring

CVSS v3: 8.2 (HIGH)

CVSS:3.1/AV:N/AC:L/PR:N/UI:N/S:U/C:N/I:H/A:L

Weaknesses (CWE)

CWE-306

References & Reports

Advisories, patches, and third-party reports

https://github.com/zitadel/zitadel/security/advisories/GHSA-4hgj-wm6c-q7p2
https://www.vulncheck.com/advisories/zitadel-3.0.0-before-4.18.0-unauthenticated-username-change-via-login-v1

Source: NIST NVD · Data may lag official sources by up to one minute