Mercurial is a distributed Source Control Management system.
Jakub Wilk discovered a directory traversal vulnerabilty in the applydiff() function in the mercurial/patch.py file.
A remote attacker could entice a user to import a specially crafted patch, possibly resulting in the renaming of arbitrary files, even outside the repository.
There is no known workaround at this time.
All Mercurial users should upgrade to the latest version:
# emerge --sync
# emerge --ask --oneshot --verbose ">=dev-util/mercurial-1.0.1-r2"