Fluxbb 1.5.11 is affected by a denial of service (DoS) vulnerability by sending an extremely long password via the user login form. When a long password is sent, the password hashing process will result in CPU and memory exhaustion on the server.
FluxBB 1.5.11 is affected by cross-site scripting (XSS in the Blog Content component. This vulnerability can allow an attacker to inject the XSS payload in "Blog Content" and each time any user will visit the blog, the XSS triggers and the attacker can able to steal the cookie according to the crafted payload.