Recently, Google had to roll back an update to its reCaptcha script after discovering a bug that specifically affected users of Mozilla Firefox on Windows. The issue came to light when users began reporting that reCaptcha stopped functioning correctly in the latest version of Firefox, showing an endlessly spinning circle instead of the usual captcha challenge. This problem was widely discussed on platforms like Twitter and Reddit, and was confirmed by BleepingComputer through direct testing.
The root of the issue was traced back to a change in the reCaptcha script that interfered with how it detected dark mode in Firefox for Windows. The script tried to modify the background color of a div using document.body.removeChild before the DOM was fully loaded, leading to a script error because document.body wasn’t available at that point. This mistake caused the reCaptcha to fail to load properly, leaving users unable to complete interactions that required captcha verification.
As a temporary workaround, users found that changing their browser’s user agent to mimic Microsoft Edge or Google Chrome allowed reCaptcha to function again. Meanwhile, a Mozilla Firefox software engineer confirmed that the issue stemmed from Google’s script and not the Firefox browser itself. Google acknowledged the problem and began working on a fix to resolve the error.
In response to the bug, Google acted quickly to roll back the reCaptcha script to a previous version, which resolved the issue for Firefox users. This swift action helped to minimize disruption and confirmed that the initial problems with reCaptcha were due to an unintentional error in the script update rather than any deliberate action by Google. The collaborative effort between Mozilla and Google ensured that the service was restored without significant downtime for users.
