MongoDB session serialization updated for higher reliability

We’ve updated the MongoDB session serialization format to improve consistency and resilience. Deployments that read existing session documents or rely on the previous format may encounter read/write failures until upgraded or migrated. Plan and test your upgrade to avoid session interruptions.

Details

Affects any deployment persisting sessions in MongoDB or using custom session handling
Recommended steps: back up your session collection, validate read/write behavior in staging, and coordinate a rolling upgrade to ensure all components use the new format before sharing the same collection
Consider a maintenance window or session regeneration if strict continuity is required

Who this is for: Teams using MongoDB for session state, especially those with multi-service deployments or custom integrations.