Drupal < 8.6.10 / < 8.5.11 - REST Module Remote Code Execution

Analyzing the patch By diffing Drupal 8.6.9 and 8.6.10, we can see that in the REST module, FieldItemNormalizer now uses a new trait, SerializedColumnNormalizerTrait. This trait provides the checkForSerializedStrings method, which in short raises an exception if a string is provided for a value...