Templating...

Invalid selector characters

⚠ Browser differences

This vector uses an import inside a CSS string to test which characters cause an invalid CSS selector.

Shazzer Master

Created byhackvertor

Created Aug 6, 2026

Updated Sep 5, 2026

Unable to render tweet button

Detecting browser...

CategoryCSS Parsing

VisibilityPublic

TypeXSS

CharsetUTF-8

Template used:

<style>
$[chr]{position:"
}@import'data:text/css,%23x{color:red}';
</style>
<div id="x">test</div>

Code used after fuzz:

window.getComputedStyle(x).color === 'rgb(255, 0, 0)' && log($[i])

Sample payloads

<style>
0x01{position:"
}@import'data:text/css,%23x{color:red}';
</style>
<div id="x">test</div>

<style>
0x02{position:"
}@import'data:text/css,%23x{color:red}';
</style>
<div id="x">test</div>

<style>
0x03{position:"
}@import'data:text/css,%23x{color:red}';
</style>
<div id="x">test</div>

<style>
0x04{position:"
}@import'data:text/css,%23x{color:red}';
</style>
<div id="x">test</div>

<style>
0x05{position:"
}@import'data:text/css,%23x{color:red}';
</style>
<div id="x">test</div>

<style>
0x06{position:"
}@import'data:text/css,%23x{color:red}';
</style>
<div id="x">test</div>

<style>
0x07{position:"
}@import'data:text/css,%23x{color:red}';
</style>
<div id="x">test</div>

<style>
0x08{position:"
}@import'data:text/css,%23x{color:red}';
</style>
<div id="x">test</div>

<style>
0x09{position:"
}@import'data:text/css,%23x{color:red}';
</style>
<div id="x">test</div>

<style>

{position:"
}@import'data:text/css,%23x{color:red}';
</style>
<div id="x">test</div>

<style>
0x0B{position:"
}@import'data:text/css,%23x{color:red}';
</style>
<div id="x">test</div>

<style>
0x0C{position:"
}@import'data:text/css,%23x{color:red}';
</style>
<div id="x">test</div>

<style>

{position:"
}@import'data:text/css,%23x{color:red}';
</style>
<div id="x">test</div>

<style>
0x0E{position:"
}@import'data:text/css,%23x{color:red}';
</style>
<div id="x">test</div>

<style>
0x0F{position:"
}@import'data:text/css,%23x{color:red}';
</style>
<div id="x">test</div>

<style>
0x10{position:"
}@import'data:text/css,%23x{color:red}';
</style>
<div id="x">test</div>

<style>
0x11{position:"
}@import'data:text/css,%23x{color:red}';
</style>
<div id="x">test</div>

<style>
0x12{position:"
}@import'data:text/css,%23x{color:red}';
</style>
<div id="x">test</div>

<style>
0x13{position:"
}@import'data:text/css,%23x{color:red}';
</style>
<div id="x">test</div>

<style>
0x14{position:"
}@import'data:text/css,%23x{color:red}';
</style>
<div id="x">test</div>