WikiDocs before 1.0.65 allows stored XSS by authenticated users via data that comes after $$\\, which is mishandled by a KaTeX parser.
https://github.com/Zavy86/WikiDocs/releases/tag/1.0.65
https://github.com/Zavy86/WikiDocs/pull/213
https://github.com/Zavy86/WikiDocs/issues/211
https://github.com/Zavy86/WikiDocs/compare/1.0.64...1.0.65
https://github.com/Zavy86/WikiDocs/commit/aa264bd046a254522da67600be73791bd4e5dafc