PYSEC-2026-2173

Glances is an open-source system cross-platform monitoring tool. Prior to version 4.5.3, the Glances XML-RPC server (activated with glances -s or glances --server) sends Access-Control-Allow-Origin: * on every HTTP response. Because the XML-RPC handler does not validate the Content-Type header, an attacker-controlled webpage can issue a CORS "simple request" (POST with Content-Type: text/plain) containing a valid XML-RPC payload. The browser sends the request without a preflight check, the server processes the XML body and returns the full system monitoring dataset, and the wildcard CORS header lets the attacker's JavaScript read the response. The result is complete exfiltration of hostname, OS version, IP addresses, CPU/memory/disk/network stats, and the full process list including command lines (which often contain tokens, passwords, or internal paths). This issue has been patched in version 4.5.3.