See GLSA 201206-15 and 201010-01 Thanks.
If I don't read those GLSAs wrong, 1.2.56 is not affected. This might be also the reason why it is still available in portage. Anyways, if Valve still wants this version, there is nothing we can do. If you do not want to use this version, you could check if Source games are also accepting more recent versions. If yes, we can lessen the version restriction.
(In reply to Mario Kicherer from comment #1) > If I don't read those GLSAs wrong, 1.2.56 is not affected. This might be > also the reason why it is still available in portage. > > Anyways, if Valve still wants this version, there is nothing we can do. Agreed. This version is not vulnerable and if a problem were to arise in future, it would almost certainly be fixed because so much software relies on it.