CRE-2025-0179
N8N Workflow Silent Data Loss During ExecutionCriticalImpact: 9/10Mitigation: 7/10
Description
N8N workflow automation platform experiences critical silent data loss where items
disappear between workflow nodes without generating error messages. This high-severity
issue affects long-running workflows (60-115+ minutes) and can cause workflows to
randomly cancel mid-execution, leading to incomplete processing and data integrity
problems. Items silently vanish between nodes, with different item counts across
the workflow pipeline, making the issue particularly dangerous for production systems
that rely on complete data processing.
Cause
* Workflow execution engine fails to properly track items between nodes in long-running workflows
* Memory management issues during extended workflow processing causing item references to be lost
* Race conditions in the worker queue system when handling multiple concurrent items
* Node-to-node data transfer mechanisms failing silently under certain load conditions
* Queue worker timeout or resource contention causing partial item processing without error reporting
* Database transaction issues where some items fail to persist between workflow stages
Mitigation
- Implement workflow item counting checks - Add validation nodes between critical
processing steps to verify item counts match expected values
- Enable comprehensive execution logging - Set N8N_LOG_LEVEL to debug and
EXECUTIONS_DATA_SAVE_ON_SUCCESS to 'all' to capture detailed execution data
- Add workflow timeout monitoring - Monitor executions that cancel around 21-23
minute mark and implement retry mechanisms for failed workflows
- Implement data integrity validation - Add checksum or validation steps at
workflow start/end to detect silent data loss
- Use error handling workflows - Configure error workflows to capture and log
execution failures, even when main workflow fails silently
- Monitor execution metrics - Set up alerting on workflow completion rates and
item processing inconsistencies
- Consider workflow segmentation - Break long workflows into smaller, more
manageable chunks to reduce exposure to the data loss issue