Telecom networks are the backbone of the digital economy. They must deliver secure, always-on connectivity at scale, supporting everything from critical national infrastructure to everyday consumer services. But cyber resilience today is no longer defined by uptime alone. It is about the ability to withstand, detect, and respond to highly targeted cyber threats that are designed to exploit the very fabric of telecom environments.

At this time last year, LevelBlue asked its experts to offer up some thoughts on what the coming year, 2025, would bring. So, with a year of hindsight, let’s keep ourselves honest and take a look to see what we got right and where we were a bit off. December 2025.

The digital storefront never sleeps, but in the first half of 2025, it has faced unprecedented hostility. According to the State of Application Security report 2025 Report, the threat landscape has shifted dramatically. E-commerce has become a primary target, with DDoS incidents in the retail and e-commerce sector spiking by 420%. Perhaps even more concerning is the vector of these attacks: attacks on APIs rose by 104%, with vulnerability exploitation increasing 13-fold.

Lefteris Tzelepis, CISO at Steelmet /Viohalco Companies, was shaped by cybersecurity. From his early exposure to real-world attacks at the Greek Ministry of Defense to building and leading security programs inside complex enterprises, his career mirrors the evolution of the CISO role itself. Now a group CISO overseeing security across multiple organizations, Lefteris brings a practitioner’s mindset to leadership and incident response.

On December 17, 2025, Cisco published an advisory detailing a new threat campaign identified on December 10, affecting the Cisco AsyncOS software used on Cisco Secure Email Gateway and Cisco Secure Email and Web Manager. The campaign is exploiting an unpatched zero-day vulnerability, which only affects deployments with the Spam Quarantine feature enabled. It allows threat actors to execute arbitrary commands with root privileges on affected devices. This feature is not enabled by default.

An Acceptable Use Policy (AUP) is a strategic compliance tool that protects people, data, and systems while setting clear expectations for technology use. A well-crafted AUP turns subjective norms into measurable rules that everyone in the organization can follow, helping mitigate legal, security, and operational risk. By standardizing acceptable behavior and linking usage rules to broader governance and risk management objectives, companies create shared understanding and accountability across teams.

React2Shell is a severe remote, unauthenticated RCE vulnerability recently uncovered in React Server Components (RSC) and the Next.js App Router — tracked as CVE-2025-55182, with CVE-2025-66478 later merged as a duplicate — that allows attackers to execute arbitrary code on servers by exploiting insecure Flight protocol deserialization (CWE-502), earning the flaw a maximum CVSS score of 10.0.