K2 identified an issue regarding insecure deserialization that affects all Endpoint SmartObject Service Types. For more information see KB003329 - Behavioral change in K2 Endpoint Service Types.
The fix is available in the following K2 versions:
- Ensure you have the correct K2 version and/or Cumulative Update installed. See KB001893 to see what Fix Pack level you have installed.
- Download the latest Fix Pack using the links in the table above for the version you require.
- Install the Fix Pack to apply the fix.