const regex = /(?<=<[^>]*)(?<=\s)(on\w+|formaction|action)=["']?(.*?)["']?(?=[\n>])/gm;
// Alternative syntax using RegExp constructor
// const regex = new RegExp('(?<=<[^>]*)(?<=\\s)(on\\w+|formaction|action)=["\']?(.*?)["\']?(?=[\\n>])', 'gm')
const str = `<img src="/name">
<a href="javascript:void">some url</a>
<a href="https://convertkit.com">URL</a>
<img src=x onerror="alert(document.domain)">
<img src=x onerror=" alert(document.domain) ">
<img src=x
onerror="alert(document.domain)"
>
<img src=x onerror=alert(document.domain)>
<button form="form1" formaction="javascript:alert(1)">Submit</button>
<form action=""></form>
<button onclick="hacked()">Hack</button>
<a href="https://convertkit.com/about?utm_content=bazard">click men</a>
<div>onmouseover=alert(1)</div>
<div> onmouseover=alert(1) </div>`;
// Reset `lastIndex` if this regex is defined globally
// regex.lastIndex = 0;
let m;
while ((m = regex.exec(str)) !== null) {
// This is necessary to avoid infinite loops with zero-width matches
if (m.index === regex.lastIndex) {
regex.lastIndex++;
}
// The result can be accessed through the `m`-variable.
m.forEach((match, groupIndex) => {
console.log(`Found match, group ${groupIndex}: ${match}`);
});
}
Please keep in mind that these code samples are automatically generated and are not guaranteed to work. If you find any syntax errors, feel free to submit a bug report. For a full regex reference for JavaScript, please visit: https://developer.mozilla.org/en/docs/Web/JavaScript/Guide/Regular_Expressions