Using YAML to parse JSON was obviously non-optimal, which is (presumably) why Rails stopped doing it in 3.1 (thus the vulnerability your refer to is only presen

Using YAML to parse JSON was obviously non-optimal, which is (presumably) why Rails stopped doing it in 3.1 (thus the vulnerability your refer to is only present in 3.0 and 2.x). W.r.t RubyGems, I hear what you're saying, but that doesn't mean there's a bug in psych. Even the feature request of adding a safe_load option strikes me as problematic...either you're limiting the markup to json with comments, or you'd have to name the option something like sort_of_safe_load.