You'll notice
The bash tool now also blocks SHELLOPTS, BASHOPTS, BASH_VERSINFO, and BASH_ARGV0 environment variables
What
The list of environment variables the bash tool refuses to let a command set now also includes SHELLOPTS, BASHOPTS, BASH_VERSINFO, and BASH_ARGV0, in addition to the existing blocks on variables like PS4 and IFS.
Why
These shell variables can change how bash itself parses and runs commands, for example turning on debugging or tracing options, so blocking them closes off ways a command could alter shell behavior unexpectedly.