CVE-2026-61628

nginx ignition has Unauthenticated Admin Account Creation via Onboarding Race Condition

Published Sep 21, 2026 CVSS 3.1 · 8.1 High EPSS < 1% KEV · Not listed
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.

Remediation

No solution or workaround provided in the CVE record

Tracking

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Advisories

Source ID Title
Github GHSA Github GHSA GHSA-pxcx-fv34-x9p5 nginx ignition has Unauthenticated Admin Account Creation via Onboarding Race Condition
History
Type Values Removed Values Added
First Time appeared Lucasdillmann
Lucasdillmann nginx-ignition
Vendors & Products Lucasdillmann
Lucasdillmann nginx-ignition
Type Values Removed Values Added
Metrics ssvc

{'options': {'Automatable': 'no', 'Exploitation': 'poc', 'Technical Impact': 'total'}, 'version': '2.0.3'}

Type Values Removed Values Added
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.
Title nginx ignition has Unauthenticated Admin Account Creation via Onboarding Race Condition
Weaknesses CWE-362
References
Metrics cvssV3_1

{'score': 8.1, 'vector': 'CVSS:3.1/AV:N/AC:H/PR:N/UI:N/S:U/C:H/I:H/A:H'}

Weaknesses

Sources

Status
PUBLISHED
Assigner
GitHub_M
Published
Updated
Sep 21, 2026, 3:12 PM
Reserved
Jul 10, 2026, 5:38 PM
Status
Awaiting Analysis
Published
Sep 21, 2026, 3:17 PM
Modified
Sep 23, 2026, 6:25 PM