phlex is an open source framework for building object-oriented views in Ruby. There is a potential cross-site scripting (XSS) vulnerability that can be exploited via maliciously crafted user data. The filter to detect and prevent the use of the "javascript:" URL scheme in the "href" attribute of an "<a>" tag could be bypassed with tab "\t" or newline "\n" characters between the characters of the protocol, e.g. "java\tscript:". This vulnerability is fixed in 1.10.1, 1.9.2, 1.8.3, 1.7.2, 1.6.3, 1.5.3, and 1.4.2. Configuring a Content Security Policy that does not allow "unsafe-inline" would effectively prevent this vulnerability from being exploited.