Do you have to believe in sola Scriptura to be saved?
Wow, a very good and insightful question. Being serious here. I believe you find God's complete Truth in the scriptures and His plan of salvation. This what I believe:
2 Timothy 3:
14 But you must continue in the things which you have learned and been assured of, knowing from whom you have learned them, 15 and that from childhood you have known the Holy Scriptures, which are able to make you wise for salvation through faith which is in Christ Jesus.
16 All Scripture is given by inspiration of God, and is profitable for doctrine, for reproof, for correction, for instruction in righteousness, 17 that the man of God may be complete, thoroughly equipped for every good work.
So as not to dodge you direct question...From the above passage I believe all Truth we need to know about salvation, God's Glory and how to live holy lives acceptable to Him are in His Written Word.
Let me please ask a counter question...What not contained in scriptures is necessary for all Truth we need to know about salvation, God's Glory and how to live holy lives acceptable to Him?
No.
Salvation is by grace thorough faith in Christ.
Now, if you don't accept that Scripture alone is indeed all we need to know for salvation and sanctification, that will leave you open to deception, but that's a different issue.