PubNub Status

## Problem Description, Impact, and Resolution  At 19:50 UTC on June 10, 2026, we observed a small fraction of publishes originating from US-EAST-1 failing to replicate to subscribers globally. We removed the degraded publisher pod from service and the issue was resolved at 21:21 UTC on June 10, 2026.  The root cause of the incident was triggered by a single process that fell into a degraded state where it continued receiving inbound traffic and passing health checks, but traffic sent outbound from the process was failing at an abnormally high rate. Our automated health check/recovery system did not auto-detect and replace the degraded process because its health check API reported itself as healthy.  ## Mitigation Steps and Recommended Future Preventative Measures  To prevent a similar issue from occurring in the future, we are improving the data within our health check APIs to return more complete performance metrics over a rolling time window. We are enhancing the issue detection logic to detect more patterns that infer process failure, even if the process itself is reporting as healthy.

Services have returned to normal. 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].

The PubNub Technical Staff identified that failures are limited to publishes from US-East and has identified, have applied a fix, and are now monitoring the results. If you are experiencing issues that you believe to be related to this incident, please report the details to PubNub Support ([email protected]).

Starting at 17:00 UTC on June 10, a subset of publishes originating from the North America POP failed to replicate to subscribers globally. PubNub Technical Staff is investigating, and more information will be posted as it becomes available.

### **Problem Description, Impact, and Resolution**  At approximately **13:20 UTC on June 9, 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 **13:48 UTC on June 9, 2026**. ‌ This issue occurred because we did not have sufficient automated controls and isolation processes in place to protect shared infrastructure from this type of exceptional traffic pattern. As a result, the increased load affected multiple services before 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 exceptional load patterns so they can be identified and contained earlier without cascading impact across dependent services.

From 13:20 to 13:48 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].