Spinnaker has uon-safe yaml deserialization, allowing RCE when using specific types
Description
Published to the GitHub Advisory Database
Jun 22, 2026
Reviewed
Jun 22, 2026
Last updated
Jun 22, 2026
Impact
There's an unsafe YAML processing vulnerability that bypasses safe deserialization. This impacts users when when performing:
The usage of a non-safe constructor use allows arbitrary loading of Java classes leading to RCE.
Patches
2025.3.3, 2026.0.3 and 2025.4.4.
Workarounds
Disable the CloudFormation system and cloudfoundry baking operations.
Resources
Join Spinnaker on Slack for more information!
References