LOW: No need to upgrade unless there are new features you want to use.
MODERATE: Program an upgrade of the server, but it's not urgent.
-HIGH: There is a critical bug that may affect some part of users. Upgrade!
+HIGH: There is a critical bug that may affect a subset of users. Upgrade!
CRITICAL: There is a critical bug affecting MOST USERS. Upgrade ASAP.
--------------------------------------------------------------------------------
+---[ Redis 2.5.13 (2.6 Release Candidate 7) ]
+
+UPGRADE URGENCY: HIGH
+
+* [BUGFIX] Theoretical bug in ziplist fixed.
+* [BUGFIX] Better out of memory handling (Log produced in log file).
+* [BUGFIX] Incrementally flush RDB file on slave side while performing the
+ first synchronization with the master. This makes Redis less
+ blocking in environments where disk I/O is slow.
+* [BUGFIX] Don't crash with Lua's redis.call() without arguments.
+* [BUGFIX] Don't crash after a big number of Lua calls on 32 bit systems
+ because of a failed assertion.
+* [BUGFIX] Fix SORT behaviour when called from scripting.
+* [BUGFIX] Adjust slave PING period accordingly to REDIS_HZ define.
+* [BUGFIX] BITCOUNT: fix crash on overflowing arguments.
+* [BUGFIX] Return an error when SELECT argument is not an integer.
+* [BUGFIX] Blocking operations on lists were completely reimplemented for
+ correctness. Now blocking list ops and pushes originated from
+ Lua scripts will play well together and will be replicated
+ and transmitted to the AOF correctly.
+* [IMPROVED] Send async PING before starting replication to avoid blocking if
+ master allows us to connect but it is actually not able to reply.
+* [IMPROVED] Support slave-priority for Redis Sentinel.
+* [IMPROVED] Hiredis library updated.
+
---[ Redis 2.5.12 (2.6 Release Candidate 6) ]
UPGRADE URGENCY: MODERATE.