CVE-2026-109371 ZITADEL 3.0.0 before 4.18.0 Unauthenticated Username Change via Login V1
Unauthenticated attackers can change usernames of any user, including admins, via the Login V1 UI, causing lockouts and potential privilege escalation.
- Exploited in the wild
- Not known
- Login needed
- Not needed
- Attackable
- Over the internet
- Victim action needed
- Not needed
- Fix
- None listed
What is CVE-2026-109371?
CVE-2026-109371 is a high-severity missing authorization vulnerability in zitadel, published on 12 Oct 2026. An attacker can exploit it over the internet without logging in, with no action from the victim.
Official 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.
Weakness: CWE-306
Which versions are affected by CVE-2026-109371?
How do I fix CVE-2026-109371?
No fix has been published for CVE-2026-109371 yet. Limit exposure of the affected software until one is available.
Upgrade, and check permissions on every request on the server, not only in the interface. More about Missing authorization.
Is CVE-2026-109371 being exploited?
There is no known exploitation of CVE-2026-109371 in the wild and no public exploit code.
Sources
Also known as GHSA-2464-29qv-3mj7, GHSA-4hgj-wm6c-q7p2.