Description
In Jenkins 2.587 and earlier, LTS 2.580.1 and earlier, the HTTP endpoint for creating the first user account does not check whether the setup wizard has been completed, resulting in a race condition that allows unauthenticated attackers to create an administrator account while the initial user account is being replaced.
Affected products
jenkins: jenkins
References1
- www.jenkins.io/security/advisory/2026-10-28/#SECURITY-4122 MitigationVendor Advisory
Metrics
- CVSS 3.1
-
8.1
HIGH
Score source: NVD
CVSS:3.1/AV:N/AC:H/PR:N/UI:N/S:U/C:H/I:H/A:H - EPSS — exploit probability
- 0% percentile: 18 · as of 3 November 2026
- CWE
- CWE-362
Could this be exploited in your environment?
A patch closes the known hole. A penetration test shows what an attacker can still reach — with proof.