Late last month, Anthropic — the company behind the Claude family of models — announced Claude Mythos, a preview release of an AI model which has changed how organizations think about AI-assisted threats.
What makes Mythos different from prior AI models wasn't just raw performance. It's the things that Mythos can do on its own without human guidance at scale:
It can find previously unknown security vulnerabilities (zero-days) in major operating systems & browsers, faster than any human researcher or prior automated tool could discover them.
It can generate working exploit code without needing to set up elaborate configurations.
It identified a vulnerability in a major open-source project that had gone undetected for over 27 years.
Between controlled testing & its predecessor, there were some huge gaps. Earlier models succeeded in generating functional exploits only a handful of times under structured conditions. While Mythos successfully generated functional exploits hundreds of times autonomously, after a single prompt.
Again, these tests were conducted internally by Anthropic & the company has taken significant steps to ensure responsible disclosure of the vulnerabilities found. However, the Capability exists now. And once capabilities exist, they spread.
It would be wrong to view Mythos as an isolated event. The trajectory of offensive security Capability enabled by AI has been building for well over one year:
In mid 2025, an autonomous AI system topped HackerOne's us leaderboard — the first time a non-human was ranked above every human security researcher on the platform. Immediately following this, Google announced their AI-based security research tool could discover and reproduce real zero-day vulnerabilities within widely used open source software in 20 ways. Late in 2025 researchers at DARPA’s aixcc competition demonstrated AI systems that could find multiple dozens of vulnerabilities in tens of millions of lines of code in hours.
By November 2025 Anthropic disclosed that state sponsored groups utilized AI tools to run full cyber attack chains — including initial reconnaissance through data exfiltration — against approximately 30 global targets.
Mythos represents the current peak of that curve. But that curve continues to go upward.
Here is the core challenge that leaders in security organizations are grappling with today: the same capabilities that make AI useful for finding vulnerabilities also make AI useful for exploiting those vulnerabilities.
Historically defenders have always had a structural disadvantage. Attackers only needed to identify one way into an organization; defenders needed to protect everything. AI sharpens that disadvantage considerably.
Prior to AI assisted discovery, the window between when a vulnerability became known & was actively weaponized typically ranged between days & weeks. This provided organizations enough time to receive a patch, test it, & deploy it before wide-scale exploitation occurred. That window has compressed — in many documented cases during 2026 — to less than 24 hours.
Furthermore, the skill floor required to execute complex attacks has decreased dramatically. Capabilities that once required nation-state resources — multi stage exploit chains, autonomous attack orchestration — will soon be available to a much broader class of threat actors as these models proliferate.
Anthropic responded quickly to limit the damage created by Mythos. The company coordinated a large-scale multi party vulnerability disclosure effort — providing early access to Mythos to a select group of critical infrastructure providers, major software vendors, & open-source maintainers so they could patch their products before vulnerabilities were publicly revealed.
While the scope of the effort is unprecedented, it does not provide unlimited coverage. The world’s total exploitable attack surface is substantially larger than any partner ecosystem designed to address it. Thus, most organizations — including virtually all small & mid sized businesses — are outside of the partner program and are subject to waiting for normal channels to distribute fixes — often with little insight into what is coming.
If you operate it or security functions in small/mid size businesses, a few items deserve your immediate attention.
Patching needs to move faster. The time between a vendor releases a fix & a workable exploit is developed using reverse engineering techniques powered by AI is shrinking rapidly. Thus a fix sitting in your queue for two weeks creates meaningful risk in a way it did not create two years ago.
You should stress test your incident response plans. Most organizations have playbooks for handling one significant incident per time period. However, the number of newly disclosed AI based vulnerabilities is increasing daily. Thus the probability of having several high severity incidents occur simultaneously over the course of a week is no longer hypothetical.
When an attacker can gain administrative access to your environment in minutes — one recent example was eight minutes — detection fire speed & team response speed may determine whether your incident becomes catastrophic or contained.
Now is the time for risk tolerance discussions. If your leadership team’s understanding of cybersecurity risk is based upon the threat landscape of three years ago, then decisions regarding cybersecurity investment made by your leadership team may not reflect your actual exposure. Therefore it is important to discuss this topic prior to an incident mandates discussion.
There is genuine reason for optimism here — and we believe this reason must be stressed.
The same AI capabilities that are accelerating offense can be leveraged for defense. AI-powered vulnerability scanning can help organizations identify weaknesses in their own code and infrastructure prior to attackers identifying them. Similarly, AI-aided security operations can help lean teams respond more quickly. The tools currently exist — the gap today primarily exists between awareness & adoption on the defensive side.
Organizations that navigate this period successfully will not necessarily be those with the largest budgets devoted to cybersecurity. Instead, they will be those who respond most rapidly to understand their true exposure, harden fundamentals & layer-in necessary detection & response capabilities.
If you are left wondering where your organization currently stands after reading this post — that is the correct question to ask yourself. Performing a cybersecurity assessment provides the fastest path toward developing an accurate picture of your present day exposure — not a checklist based upon past thinking — but rather an accurate representation of what an attacker would discover if he came looking today.
At NexusTek we work with small & mid sized businesses across industries to develop accurate pictures of their true risk posture & establish cybersecurity programs tailored to the specific threat environment your organization actually faces — not how you thought the threat environment looked three years ago.
Contact us to get started with a cybersecurity assessment today.