The Tor Project has announced
that it is planning to actively stop supporting Tor 0.4.8 and earlier
C Tor versions soon.
Usually, we try not to break existing releases, even if they are
unsupported, unless we have a pretty good reason. In this case, we
have several reasons. [...]
The most important reason is this: in 0.4.9, we have made some
former fields in our directory data obsolete -- specifically, TAP
onion keys and family
lines. Removing these fields will let us save a great deal of
client directory bandwidth for everyone. This, in turn, will make all
Tor clients bootstrap a little faster, especially those on slow
connections. But when we remove these fields, clients and relays
running earlier versions of Tor will no longer work, since they expect
the TAP onion keys to be present. Therefore, in order to deliver
improved performance faster, we need to accelerate the date on which
0.4.8 will stop working.
The target sunset date is currently September 1,
2026, after which any version prior to Tor 0.4.9 will cease to work on
the network. The first stable release in the 0.4.9.x series was
announced
in February 2026, and the Tor 0.4.8.x series reached end of life on
June 1.