CVE-2026-61628 nginx ignition has Unauthenticated Admin Account Creation via Onboarding Race Condition
Unauthenticated attackers can create admin accounts via a race condition in nginx ignition's onboarding endpoint, leading to full system compromise.
- Exploited in the wild
- Not known
- Login needed
- Not needed
- Attackable
- Over the internet
- Victim action needed
- Not needed
- Fix
- Available
What is CVE-2026-61628?
CVE-2026-61628 is a high-severity vulnerability in lucasdillmann nginx-ignition, published on 21 Sep 2026. An attacker can exploit it over the internet without logging in, with no action from the victim.
Official description
nginx ignition is a user interface for the nginx web server. Prior to version 2.41.1, `POST /api/users/onboarding/finish` is registered as anonymous (unauthenticated) and creates a user with full ReadWrite admin permissions. Because the handler uses a check-then-act (TOCTOU) pattern between the "onboarding already completed?" check and the user-creation write, with no atomic guard, a remote unauthenticated attacker who can reach an instance in its pre-onboarding state can create an administrator account for themselves — and concurrent requests can create multiple admin accounts in a single race. Version 2.41.1 patches the issue.
Weakness: CWE-362
Which versions are affected by CVE-2026-61628?
3 open source packages ship an affected version, including github.com/lucasdillmann/nginx-ignition.
| Package | Affected | Fixed in |
|---|---|---|
github.com/lucasdillmann/nginx-ignition Go | All versions | None |
github.com/lucasdillmann/nginx-ignition Go | All versions | 0.0.0-20260621194639-0586b4e55ab |
github.com/lucasdillmann/nginx-ignition Go | All versions | 0.0.0-20260621194639-0586b4e55ab |
How do I fix CVE-2026-61628?
Upgrade github.com/lucasdillmann/nginx-ignition to 0.0.0-20260621194639-0586b4e55ab or later.
Is CVE-2026-61628 being exploited?
It is not confirmed as exploited in the wild, but public exploit code for CVE-2026-61628 exists.
Public exploit code: 1 proofs of concept on GitHub.
Sources
Also known as GHSA-pxcx-fv34-x9p5, GO-2026-6540.