Characters allowed in middle of HTML tag name

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65.5k

65.5k

Characters that are may be part of HTML tag names. These are less strict that the first character

Created on: Friday, January 30, 2026 at 12:50:42 PM

Updated on: Friday, January 30, 2026 at 12:50:42 PM

Category: HTML Parsing

Vector visibility: Public

Vector type: XSS

Vector charset: UTF-8

<a$[chr] id="test">

document.getElementById('test').tagName.length > 1 && log(i)