A bug in Google Analytics for Firebase, a service used by developers to track user behavior in mobile applications, caused widespread crashes in iOS apps during the night of September 28 to 29, 2026. The problem was traced to a malformed data packet sent by Google's servers, which triggered crashes in apps that used the Firebase component. This issue affected iOS and iPadOS apps that integrated the Google Analytics SDK for Apple platforms, but Android devices were not impacted. The first crashes were reported on September 29 at 2:41 AM Paris time (17:41 in California), and the fix was fully deployed at 4:52 AM, taking about 2 hours and 11 minutes to resolve. Google stated that the issue was quickly addressed, but due to caching behavior, some app instances may still experience crashes up to 4 hours after the fix was deployed. Developers noted that the number of crashes significantly decreased after the update, although some users may still face issues. The incident did not require any action from app developers or updates from the App Store, as the error originated from Google's side. Some developers reported tens of thousands of crashes recorded on a single application, showing how large the impact was. However, Google did not provide a global figure for the number of affected users. The cause was identified as a malformed data packet sent by Google's servers. According to Google, everything returned to normal by Tuesday, September 29, 2026, at 08:52 AM Paris time. However, some users reported that the issue was still not fully resolved for them. At the time of publishing, not all sources had fully explained the cause of the incident.