rails 7.0.3.1: Psych::DisallowedClass: Tried to load unspecified class: Symbol

[sobakasu]

We get an error with rails 7.0.3.1. Downgrading to rails 7.0.3 fixes the error.

The error is: Psych::DisallowedClass: Tried to load unspecified class: Symbol

steps to reproduce:

errors = ActiveModel::Errors.new(model)
errors.add(:attribute, :blank)
errors[:attribute]

another workaround:

config.active_record.yaml_column_permitted_classes = [Symbol, Date, Time]

seems to be caused by https://discuss.rubyonrails.org/t/cve-2022-32224-possible-rce-escalation-bug-with-serialized-columns-in-active-record/81017

[timfjord]

Thanks for reporting the issue

I think the only thing we can do now is to wait once the issue will be fixed in Rails.
In the meantime, we should use the provided workaround