From September 14-17, ethical hackers from across Austria gathered in Linz for the finals of the Austria Cyber Security Challenge 2026. The ACSC takes place once a year and is organized by the nonprofit association Cyber Security Austria and the Cybersecurity Center CySec at TU Wien. The event brought together the best participants from the qualification rounds in a bid to solve Capture-The-Flag (CTF) challenges. Participants competed in two age groups and an open category: ages 14 to 20 (Juniors), ages 21 to 25 (Seniors), and an open class for anyone interested in ethical hacking, regardless of age or education.

The qualification phase unfolded in two waves, presenting fresh challenges—even for seasoned ACSC veterans. Several tasks were developed in collaboration with the organizers of the German and Swiss Cyber Security Challenges, further raising the bar. During the qualification rounds, participants competed individually. The top 21 juniors and seniors, as well as the top 20 open category participants, advanced to the finals, where they could build their own teams within their respective categories.

In previous years, participants took part in Jeopardy-style challenges, scoring points for each challenge solved. For this year’s finale, the format was different. Over the course of eight hours, teams competed in an attack-and-defense challenge: they had to find and fix the same set of security weaknesses in their own systems while simultaneously attempting to exploit weaknesses in other teams’ systems. Success depended not only on each participant’s technical expertise, but also on effective group organization and teamwork, as well as the ability to quickly adapt and perform under pressure—skills that IT security professionals rely on every day to respond to cyber threats.

Another highlight and new addition to the event was a “Live CTF” contest. Ten players (one from each finalist team) went head-to-head in a 30-minute challenge, competing individually for points that would count towards their team’s score. The faster they solved the challenge, the more points they earned. Across three rounds, live commentary and live streams of the players’ screens gave the audience a real-time view of the action. Additionally, participants could engage in a Siemens-sponsored hardware challenge this year, in which they were able to solve a number of challenges and submit flags for points.