What
A path safety check now refuses a path when it cannot be fully resolved. This covers following a symlink (a file that points to another location) and expanding ~ (shorthand for your home folder). Before, only the existing refusal cases applied.
Why
A path whose real destination is unclear is refused instead of being used as if it were safe.
Something disagreesSomething we can check disagrees with this entry, or the writer said they could not settle it.
The writer flagged doubt
The finding does not say which features rely on this check.