Following errors were logged on my website, should I be concerned or can I just ignore them?

SecurityError: Permission denied to access property "dispatchEvent" on cross-origin object - url: moz-extension://f985b107-bcb9-45d4-95c4-b1bb39443725/js/inject.js - line: 65 - column: 0 - error: SecurityError: Permission denied to access property "dispatchEvent" on cross-origin object (browser: Firefox 55)

Thanks!

Following errors were logged on my website, should I be concerned or can I just ignore them?

SecurityError: Permission denied to access property "dispatchEvent" on cross-origin object - url: moz-extension://f985b107-bcb9-45d4-95c4-b1bb39443725/js/inject.js - line: 65 - column: 0 - error: SecurityError: Permission denied to access property "dispatchEvent" on cross-origin object (browser: Firefox 55)

Thanks!

• javascript
• security
• cross-domain

• This is a duplicate of: stackoverflow./questions/25845203/understanding-cors ( I'm out of flags ) – Steven Stark Commented Mar 8, 2019 at 18:47
• 10 Read the error message more carefully. They aren't on your website. url: moz-extension://f985b107-bcb9-45d4-95c4-b1bb39443725/js/inject.js. They are ing from a browser extension. We have no idea if you should be concerned or not, we don't know what extensions you have installed or how trustworthy they are (and this isn't a programming problem unless you are writing the extension yourself). – Quentin Commented Apr 5, 2019 at 9:23
• 4 I'm seeing the same thing from an unknown user's firefox extension. Doesn't reproduce for me locally. I would love to know if anyone figures out what the extension is. – chrishiestand Commented Jun 28, 2019 at 18:10
• anytime you see "SecurityError" you should be concerned - something is trying to do something it probably shouldn't be. if after you have investigated and can discount it because of - as suggested - unknown extensions, and that it is harmless, then you can sleep peacefully – batman567 Commented Apr 6, 2021 at 14:14

1 Answer 1

You should not be concerned, you can ignore them.

It es from extension of a firefox browser: url: moz-extension://f985b107-bcb9-45d4-95c4-b1bb39443725/js/inject.js who's trying to attach event but CrossOrigin query is not allowed.

Good documentation explaining CORS (Cross Origin Resource Sharing) : https://developer.mozilla/en-US/docs/Web/HTTP/CORS