Jenkins 2.550 and earlier, LTS 2.541.1 and earlier accepts Run Parameter values that refer to builds the user submitting the build does not have access to, allowing attackers with Item/Build and Item/Configure permission to obtain information about the existence of jobs, the existence of builds, and if a specified build exists, its display name.
Exploitability
AV:NAC:LPR:LUI:NScope
S:UImpact
C:LI:NA:N4.3/CVSS:3.1/AV:N/AC:L/PR:L/UI:N/S:U/C:L/I:N/A:N