We have identified and fixed a path traversal vulnerability in various Confluence actions. By exploiting a path traversal vulnerability, attackers can retrieve any file on the server that is running Confluence, based on the permissions of the user under which Confluence is running. Path traversal attacks are also called 'directory traversal' or dot-dot-slash (../) attacks.
You can read more about path traversal attacks at Open Web Application Security Project (OWASP) and other places on the web:
Please refer to the security advisory for details of the vulnerability, risk assessment and mitigation strategies: