Is PubNub down?

As of 12:15 UTC, Users in our US East PoP are currently experiencing an issue with Publish and Subscribe service that is causing some messages to not appear in calls to that service. No errors are being returned from the service, despite messages not being returned correctly. We are investigating the issue.

As of 13:55 UTC, the issue affecting Publish and Subscribe services in the US East PoP has been mitigated. Synthetic monitoring has returned to normal, and no missed messages have been detected. The incident is currently believed to have been related to a monitoring failure. Further investigation is ongoing, and the service continues to be monitored closely.

With no further issues observed for the past 30 minutes, the incident has been resolved. We will follow up soon with a root cause analysis. If you believe you experienced an impact related to this incident, please report it to PubNub Support at [email protected].

### **Problem Description, Impact, and Resolution**  On Tuesday, August 25th, 2026, at 12:10 UTC, our internal monitoring alerted us to an issue where a very small subset of messages within one availability zone of one region \(our US East point of presence\) may not have been immediately delivered to subscribers in that same region. All messages were persisted normally within PubNub Persistence service, **thus no message data was lost.** Traffic to or from any other region or AZ was not affected, and no other PubNub services were affected. No customers reported impact. ### **Root Cause** During planned internal load testing, a group of internal routing servers was removed from service. Due to a configuration flaw, their network addresses were not fully retired and remained cached by our publishing layer. This presented no problem for the most part. However, one address was subsequently reassigned to an unrelated internal component that responded normally on the same protocol and port. Because that response appeared successful, the publishing layer received no error, and messages sent to that address were routed incorrectly. A rolling restart of the affected servers cleared the outdated addresses at 13:25 UTC. ### **Mitigation Steps and Recommended Future Preventative Measures**  * Once the affected servers were identified, a rolling restart was performed to clear the outdated routing addresses. * Following an investigation that confirmed the root cause, a fix ensuring outdated internal routing addresses are correctly retired was deployed to all publishing servers worldwide on August 25th, 2026 at 22:00 UTC.

From 13:55 to 14:15 UTC, users globally may have experienced errors with failure on Publish, and published messages may not have been received by subscribers. We also experienced errors and failures with PubNub Functions, and delays with Events & Actions during the period. Services have returned to normal and we are actively monitoring. A root cause analysis will be published in the coming days. If you believe you were impacted and would like to speak with us, please report impact to [email protected].

### **Problem Description, Impact, and Resolution**  At approximately **13:55 UTC on Aug 14, 2026**, we observed elevated publish errors and message replication failures in our publish/subscribe service, which also caused latency in other PubNub services globally. Customers may have experienced increased publish error rates, delayed or missed message delivery, delayed message persistence, and increased latency for Functions and Events & Actions workflows. ‌The root cause of the incident was an unusually large concentration of global publish traffic that was not limited by our throttling layers. That traffic created resource pressure in the publish and replication layers, increased load on storage systems, and caused downstream processing delays in dependent services. We mitigated the issue by adjusting targeted traffic controls, increasing capacity for affected publish and replication components, and isolating the high-volume traffic pattern to reduce broader platform impact. The issue was resolved at approximately **14:15 UTC on Aug 14, 2026**. ‌This issue occurred because of an issue with our automated controls specific to this exceptional traffic pattern. As a result, the increased load affected multiple services before a mitigation could be fully applied.  ### **Mitigation Steps and Recommended Future Preventative Measures** To prevent a similar issue from occurring in the future, we have isolated the identified high-volume traffic pattern onto dedicated infrastructure and also increased baseline capacity for the affected components across our PoPs. We are also further strengthening our traffic detection and management processes for this exceptional load pattern so it will be identified and contained earlier without cascading impact across dependent services.