In RestEasy Reactive implementation of Quarkus the insecure File.createTempFile() is used in the FileBodyHandler class which creates temp files with insecure permissions that could be read by a local user.
Exploitability
AV:LAC:LPR:LUI:NScope
S:UImpact
C:LI:NA:N3.3/CVSS:3.1/AV:L/AC:L/PR:L/UI:N/S:U/C:L/I:N/A:NOther