Minor incident

Anaplan: Platform Alerts

Affected: us1: Data Center - US East

Current status of Anaplan: Operational — live Anaplan status

Timeline

1. Oct 27, 2026, 13:22 UTC
   investigating
   We are currently investigating an issue resulting in some customers experiencing issues when logging on to the Anaplan Platform. We are working to resolve this issue as quickly as possible and will provide updates every 30 minutes or upon resolution.
2. Oct 27, 2026, 13:39 UTC
   identified
   Our Vendor have identified a third-party issue affecting some customers whose traffic passes through external vendor firewalls following recent firmware upgrades. Impacted customers may observe the following behaviours: ERR_TIMED_OUT errors on standard HTTPS Our teams are actively monitoring the vendor's remediation efforts to ensure services are fully stabilized. We will provide further updates in 60 minutes or upon resolution.
3. Oct 27, 2026, 14:52 UTC
   identified
   Our Vendor have identified a third-party issue affecting some customers whose traffic passes through external vendor firewalls following recent firmware upgrades. Impacted customers may observe the following behaviours: ERR_TIMED_OUT errors on standard HTTPS Our teams are actively monitoring the vendor's remediation efforts to ensure services are fully stabilized. We will provide further updates in 60 minutes or upon resolution.
4. Oct 27, 2026, 15:03 UTC
   monitoring
   Service has now been restored; you should now be able to resume normal activities. We will continue to monitor the platform to ensure no additional issues arise. If you have any questions, concerns, or continue to experience issues, please do not hesitate to contact Anaplan Support. We will provide a final update to you when we consider this situation fully resolved.
5. Oct 27, 2026, 15:41 UTC
   resolved
   We have confirmed that the issue is now resolved. We deeply apologize for any impact this issue may have caused. We appreciate your patience and partnership as we worked through this issue. We will follow up within 7 business days with a detailed root cause analysis (RCA) that will be shared on our Status Page. If you have any question or concerns, please do not hesitate to contact us at Anaplan Support.
6. Nov 6, 2026, 12:52 UTC
   postmortem
   On October 27, 2026, at 12:36 UTC, some customers in our US1 region experienced timeouts when logging in to Anaplan or opening their workspaces. **Root cause** The login disruption was caused by an automated safety filter that our content delivery network \(CDN\) provider activated to manage a sudden spike in internet traffic. The traffic spike subsided within two minutes, but the safety filter remained active and mistakenly blocked legitimate customer connections. This happened because secure connection messages sent by modern web browsers, after passing through standard corporate network security firewalls, matched the specific traffic characteristics that the safety filter was trying to block. The issue lasted for a few hours because blocked browsers kept automatically trying to reconnect, which kept the automated filter active. Anaplan's applications, login services, and internal systems worked normally throughout the event. **Recovery** Our engineering team investigated as soon as customers reported the issue and linked it to a known third-party issue that our CDN provider had reported. We worked with the CDN provider while they put a fix in place, and affected customers had normal access again by 15:03 UTC. We didn't need to change any Anaplan infrastructure or configuration. **Corrective and preventative actions** * The vendor is refining automated mitigation rules to target specific network locations by default, which will reduce the scope of any potential impact. * Cloudflare is enhancing its traffic fingerprint analysis to better differentiate between malicious activity and legitimate modern browser connection patterns. We apologize for the impact this issue has had on your operations. We're committed to the improvements outlined above to prevent similar disruptions. If you have questions or concerns, please contact Support.

Updates as published by Anaplan (original).