This tweet mentions a detected pattern that can bypass a Web Application Firewall (WAF). The user found this pattern effective on two different targets recently. They note that additional techniques or 'gadgets' are needed to fully exploit the security issue, but the pattern itself is a notable WAF bypass. Unfortunately, the tweet does not provide details about the type of vulnerability the bypass targets (such as XSS, SQLi, RCE), the specific payload used, or the WAF vendor involved. Therefore, the exact technical mechanism and scope of this bypass are not clear from this information alone.
For more insights, check out the original tweet here: https://twitter.com/xssdoctor/status/1961157668602511727