Security: 5.3.0.1 released

In version 5.3 much of the authorization control was rewritten. There
was a bug in the new code that resulted in granting write access to
read-only users or communities which were configured using the
"rocommunity" or "rouser" snmpd.conf tokens. 5.3.0.1 fixes this
problem. Users are encouraged to immediately update their
installations if they use either of these tokens. A big thanks is
owed to Robert Story who found and fixed the bug very quickly.

http://www.net-snmp.org/download/