Common XSS Payloads and How to Block Them

Cross-site scripting is still one of the easiest ways to turn a tiny frontend mistake into a full account takeover. I’ve seen teams spend weeks hardening auth flows while leaving a innerHTML assignment sitting in a comment widget like a loaded gun. The tricky part is that “XSS payloads” are not all the same. Some rely on raw <script> injection. Some abuse HTML attributes. Some hide inside JavaScript URLs, SVG, Markdown, or template rendering. If you only block one shape, the others get through. ...

May 15, 2026 · 7 min · headertest.com

XSS in ServiceNow: Where It Hides and How to Stop It

ServiceNow is one of those platforms where people assume the framework will save them. Sometimes it does. Sometimes it absolutely does not. I’ve seen teams build solid workflows, ACLs, and integrations, then quietly ship stored XSS through a widget, a Jelly page, or a badly handled g_form.addInfoMessage() call. The dangerous part is that ServiceNow mixes platform abstractions with plain old web rendering. If user-controlled data lands in HTML, JavaScript, or the DOM without the right encoding, you still have the same browser-side problem you’d have in any other app. ...

April 8, 2026 · 8 min · headertest.com