Improper Encoding or Escaping of Output in Jenkins and Jenkins LTS - CVE-2026-84655
Published: September 4, 2026
Vulnerability identifier: #VU146930
CSH Severity: Medium
CVSS v4: 5.3 [CVSS:4.0/AV:N/AC:L/AT:N/PR:L/UI:N/VC:N/VI:L/VA:N/SC:N/SI:N/SA:N]
CVE-ID: CVE-2026-84655
CWE-ID: CWE-116
Exploitation vector: Remote access
Exploit availability:
No public exploit available
Vulnerability details
The vulnerability allows a remote attacker to compromise the target system.
The vulnerability exists due to insufficient validation of user-supplied input in REST API. A remote user can inject arbitrary fields into JSON and Python API responses.
Affected software
Jenkins
Jenkins LTS
Jenkins LTS
How to mitigate CVE-2026-84655
Install updates from vendor's website.
Jenkins - update to 2.580
Jenkins LTS - update to 2.568.3
Jenkins LTS - update to 2.568.3