Medium · published October 13, 2026
ammonia is a Rust library for repairing and securing untrusted HTML. Prior to 3.3.3, 4.0.3, and 4.1.4, applications that allow the SVG animate or set elements can retain an animation whose attributeName targets href and whose value uses the javascript scheme. The sanitized SVG can therefore create a script-bearing link, and a user who clicks the link can execute attacker-controlled script in the application's origin, enabling stored cross-site scripting. This issue is fixed in versions 3.3.3, 4.0.3, and 4.1.4.