
A significant security breach has emerged within the technology sector involving Juniper MX routers, targeted by a China-nexus threat group identified as UNC3886. These compromised devices, which have reached their end-of-life stage, were infiltrated with custom Tinyshell-based backdoors. According to Mandiant’s extensive research into this breach, there is a vulnerability known as CVE-2025-21590. This vulnerability is related to improper isolation