Several fonts on OS X display some Tibetan and Arabic characters as whitespace. When used in the addressbar as part of an IDN this can be used for domain name spoofing attacks.
*Note: This attack only affects OS X operating systems. Other operating systems are unaffected.*
Name: the Mozilla project
Upstream: Khalil Zhani
Public now via upstream advisories:
In reply to comment 0:
> *Note: This attack only affects OS X operating systems. Other operating
> systems are unaffected.*
Linux belongs to the unaffected category.