Jenkins EC2 Fleet Plugin 4.2.3.539.v8fedff2a81c3 and earlier does not perform permission checks in several HTTP endpoints used to validate cloud configurations.
This allows attackers with Overall/Read permission to connect to an attacker-specified URL using attacker-specified credentials IDs obtained through another method, capturing AWS credentials stored in Jenkins.
Additionally, these HTTP endpoints do not require POST requests, resulting in a cross-site request forgery (CSRF) vulnerability.
EC2 Fleet Plugin 4.2.3.540.va6eedb7bc112 requires Overall/Administer permission and POST requests to perform these form validation actions.
// cvss v3.1 vector
CVSS:3.1/AV:N/AC:L/PR:L/UI:N/S:U/C:L/I:L/A:N
Attack vector
Network
Attack complexity
Low
Privileges required
Low
User interaction
None
Scope
Unchanged
Confidentiality
Low
Integrity
Low
Availability
None
Checked 2026-09-25 at 23:52 UTC. The most recent advisory here was published 2026-06-24. Updated continuously from NVD, GHSA, OSV and CNA feeds.