This year's Code Security Advent Calendar is the seventh consecutive one, and it invites all developers and security enthusiasts to participate. The calendar will feature 24 daily code puzzles that hide new favorite security flaws and attacker tricks, allowing participants to sharpen their security skills and have fun during December. The challenges will be hosted on Sonar's website, with solutions available online for education and future reference. Real-world code vulnerabilities from this year's security research will be used in the challenges, crafted in popular programming languages such as C, JavaScript, Java, PHP, Python, and C#. Participants can expect a mix of vulnerability types, including those related to unvalidated user input, bad configurations, and harmless-looking features that can be abused by attackers. The calendar aims to make the event enjoyable for all skill levels, with hints provided throughout the day if needed, and detailed solutions available after 24 hours.