1981596 - "SquareX Enterprise - Spreedly" causing poor performance due to leaked Blob URLs

Status: RESOLVED MOVED

(WebExtensions :: Developer Outreach, defect)

Description

[Markus Stange [:mstange]]

Profile: https://share.firefox.dev/4oo0Gyz

This was reported in bug 1981051. It appears that, over the course of a Firefox session, the add-on "SquareX Enterprise - Spreedly" (15237d20-dab3-4143-b9e7-1bc847749b7d) can create hundreds of thousands of blob URLs, which cause Firefox to slow down significantly, making simple UI actions take multiple seconds.

See attachment 9505587 [details] for an about:memory report which contains around 200 000 blob URLs from the add-on.

Comment 1

[Markus Stange [:mstange]]

Specifically there's a file called blob-proxy.html in the add-on.

Comment 2

[Rob Wu [:robwu]]

The extension ID of SquareX Enterprise - Spreedly is spreedly@onsqrx

I got that from the profile by running profile.meta.extensions from the devtools and matching the extension name in the list with the extension ID list.

Comment 3

[Simeon Vincent [:dotproto]]

I reached out to the add-on developer on Aug 7, 2025 to notify them of the issue.