Bypass Windows 7 Extended Security Updates Eligibility Simplix Pack to update Live Win7 System/ Integrate hotfixes into Win7 distribution MDL Win 7 Tool for SiMPLiX UpdatePack AiO ISO (with install.wim/esd) Creation
Windows 7 "Platinum" is updated to 2023-12-12. Just drop the Ultimate SP1 ISO to the "iso" folder and run the tool. After it's done, a new updated ISO will be saved. It does include some additions though like updated .NET Framework / .NET Core / DirectX / Visual C++ runtimes, PowerShell 5.1, updated network/USB drivers, etc. I'd consider it Vanilla+ instead of Vanilla Windows 7 if that makes any sense. So it might not be exactly what you want, if you want only the windows updates and nothing else.