Progress Software has fixed a sneaky WAF bypass vulnerability identified by CVE-2026-21876. Although the exact type of vulnerability and payload details are not provided in the tweet, this indicates that a weakness in the Web Application Firewall (WAF) product by Progress Software allowed attackers to bypass the security controls. Such WAF bypass vulnerabilities are critical because they enable malicious actors to evade detection and potentially exploit web applications behind the firewall. Users of Progress Software's WAF solution are advised to update to the latest version to protect their applications from this bypass issue. Be sure to follow official security advisories from Progress Software for more detailed information and mitigation steps.
Original tweet: https://twitter.com/ScyScan/status/2046929546310807646