To ensure you truly get a working, updated CUCM 12.5:
Use the search or browse hierarchy:
Cisco publishes these publicly. Search directly on Cisco.com: cisco cucm 125 download updated
These are available as free PDFs from Cisco’s documentation portal. To ensure you truly get a working, updated CUCM 12
Supported upgrade paths to 12.5:
Do NOT skip versions without consulting the Cisco Upgrade Guide. Use the search or browse hierarchy: Cisco publishes