CVE-2026-61628

8.1 HIGHpublic exploit available

Published 2026-09-21 · Updated 2026-09-23

AI risk analysis

Summary: The flaw allows a remote unauthenticated attacker to create a full admin account by exploiting a race condition in the onboarding process of nginx ignition.
Exploitability: Exploitation is moderately hard due to the need for timing and concurrency, and the attacker must be able to reach the pre-onboarding state of the target.
Blast radius: If exploited, the attacker gains full admin access, which could lead to complete compromise of the system and data.
Detection: No reliable host or network indicator is derivable from the published description.
Prioritized remediation: Upgrade to version 2.41.1 or later.

auth-bypasswebrace-condition

Analysis generated locally by qwen2.5:7b-instruct (no data left the box). AI-assisted — verify against primary sources before acting.

NVD 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.

CVSS vector

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

Weaknesses

CWE-362

Public exploit & PoC references

References

Data: NVD (public domain). Analysis: local $0 model. Defensive use only.