CVE-2026-61628 nginx ignition - Broken Access Control

nginx ignition < 2.41.1 contains a broken access control caused by a TOCTOU race condition in POST /api/users/onboarding/finish, letting remote unauthenticated attackers create admin accounts, exploit requires instance in pre-onboarding state.

CVSS base score 8.1 /10
High
CISA KEV
Not listed
Public exploit
Proof of concept available
Authentication
Not required
EPSS
0.43% chance of exploitation in 30 days
View the NVD record ↗

Details

Type
Broken Access Control
Impact
Privilege Escalation, Broken Access Control
CVSS vector
CVSS:3.1/AV:N/AC:H/PR:N/UI:N/S:U/C:H/I:H/A:H
Published
21 September 2026
Updated
15 October 2026
Weakness
CWE-362

Vendor fix

Update to version 2.41.1 or later.

Patching closes this CVE. It does not tell you which of your systems run the affected version, or what else is exposed alongside them.

References

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