Between July 26, 2026 at 4:38 PM PDT and July 27, at 9:15 PM PDT, some users may have experienced intermittent errors and delays when uploading files in Box. The impact was limited to a subset of customers and upload paths.

We mitigated the issue with temporary traffic controls, and service levels returned to normal by 9:15 PM PDT on July 27. Based on our investigation, the issue was related to database contention affecting upload processing. We subsequently deployed a fix addressing this contention at 2:11 PM PDT on July 28.

We are conducting a full engineering postmortem to confirm the root cause and identify additional measures to prevent recurrence. Our overview is subject to change with further analysis and findings. In the event our continuing investigation yields further substantive findings, we may publish additional analysis after the conclusion of the full engineering postmortem.

We are continuously working to improve Box and want to make sure we are delivering the best product and user experience we can. We hope we have provided some clarity here and we would be happy to answer any questions you may still have regarding this matter.

Sincerely,

The Box Team