From version 1.3.0 to version 1.9.12, and from version 2.0.0 to version 2.0.4, the Atlassian OAuth Plugin’s IconUriServlet allows remote attackers to read the content of internal network resources and/or launch an XSS attack via Server Side Request Forgery (SSRF).
We suggest that you update Jira IconURIServlet in order to fix this vulnerability.