Jenkins has a stored XSS vulnerability in node offline cause description
Date: 2026-02
Affected: maven/org.jenkins-ci.main:jenkins-core, maven/org.jenkins-ci.main:jenkins-core
Attack vector: xss
Category: vulnerability-disclosure
Severity: High
CVE: CVE-2026-27099
CWE: CWE-79
CVSS: 8 (CVSS:3.1/AV:N/AC:L/PR:L/UI:R/S:U/C:H/I:H/A:H)

Jenkins 2.483 through 2.550 (both inclusive), LTS 2.492.1 through 2.541.1 (both inclusive) does not escape the user-provided description of the "Mark temporarily offline" offline cause, resulting in a stored cross-site scripting (XSS) vulnerability exploitable by attackers with Agent/Configure or Agent/Disconnect permission.


Mitigations:

Architectural layers (MAESTRO):