Executive brief
CyberPanel 1.9.1 contains a path traversal vulnerability in the readFileContents method of the /filemanager/controller endpoint. An authenticated remote attacker with ownership of any configured domain can supply an arbitrary absolute or out-of-scope path in the fileName JSON property. Because authorization validates only domainName and does not canonicalize or restrict fileName to that domain's home directory, the application returns the contents of files readable by the CyberPanel execution identity.