[Medium] Increased FTP 530 Captcha errors

Final update

We recently addressed issues affecting Box FTP and SFTP services. We would like to take the opportunity to further explain these issues and the steps we have taken to keep them from happening in the future. From February 25th, 2026 at 9:20 AM PST to February 27th at 4:10 PM PST, some users may have experienced difficulties while working in Box. During this time, Box FTP and SFTP users may have seen CAPTCHA messages while logging in through FTP. The issue occurred due to a change in internal traffic routing which affected the Box FTP and SFTP services. We were able to resolve the issue by reverting the internal routing change and clearing CAPTCHAs for affected users. We are now working to harden the system against internal rate limiting going forward to prevent similar issues from occurring in the future.  ‌ **Analysis** On February 23rd at 8:20 AM PST, a change was made to send a subset of login traffic through a new route. After this change, no issues were observed and no customer issues were reported. On February 25th at 8:20 AM PST, a subsequent change was made to send more of the same login traffic through the new route. Roughly one hour after this change was completed, the Bo

1. Postmortem · Mar 5, 22:43 UTC
   We recently addressed issues affecting Box FTP and SFTP services. We would like to take the opportunity to further explain these issues and the steps we have taken to keep them from happening in the future. From February 25th, 2026 at 9:20 AM PST to February 27th at 4:10 PM PST, some users may have experienced difficulties while working in Box. During this time, Box FTP and SFTP users may have seen CAPTCHA messages while logging in through FTP. The issue occurred due to a change in internal traffic routing which affected the Box FTP and SFTP services. We were able to resolve the issue by reverting the internal routing change and clearing CAPTCHAs for affected users. We are now working to harden the system against internal rate limiting going forward to prevent similar issues from occurring in the future.  ‌ **Analysis** On February 23rd at 8:20 AM PST, a change was made to send a subset of login traffic through a new route. After this change, no issues were observed and no customer issues were reported. On February 25th at 8:20 AM PST, a subsequent change was made to send more of the same login traffic through the new route. Roughly one hour after this change was completed, the Box FTP service started to receive an increased rate of CAPTCHA failures, blocking users from logging in. The second routing change was identified as the root cause and reverted on February 27th at 12:49 PM PST. After revert, a number of Box FTP users needed to clear an additional CAPTCHA. Box Support
2. Resolved · Feb 27, 23:51 UTC
   After further monitoring, this incident is now considered resolved. FTP and SFTP service has been restored to full functionality. If you continue to experience any issues, please contact Box Support at https://support.box.com.
3. Monitoring · Feb 27, 22:58 UTC
   We are continuing to monitor for any further issues.
4. Monitoring · Feb 27, 21:58 UTC
   A fix has been implemented and we are monitoring the results.
5. Investigating · Feb 27, 21:15 UTC
   Box continues to investigate reports of Captcha errors issues with FTP and SFTP logins.
6. Investigating · Feb 27, 20:02 UTC
   We are investigating an ongoing issue affecting FTP and SFTP logins. We will provide more information as soon as it is available.