This tweet mentions an XSS bypass for the T-Sec Web Application Firewall (WAF). However, it does not provide the payload or specific technical details about the bypass method used. The T-Sec WAF is a security product designed to protect web applications from various attacks, including cross-site scripting (XSS). An XSS bypass means that the attacker found a way to send a malicious script that evades the T-Sec WAF's filtering mechanisms, potentially allowing the script to execute in a victim's browser. Unfortunately, the lack of payload or further details limits our ability to explain how this bypass works or how to defend against it. To better understand and mitigate such bypasses, security researchers typically share the payloads or methods used in the bypass, which can then be analyzed and used to improve WAF rules.