No, members of Congress do not generally have security clearances. There are special conditions for those who serve on intel committees but House and Senate members in general do not have clearances and it is a tricky issue as to how classified materials are shared with Congress. We need only look at all the charlatans in the clown show that is the Democrap Party to realize how dangerous it would be for a ton of classified materials to be broadly disseminated in Congress.
This particular memo should be shared, to be sure, but it will require a vote of the House to do so. Since the memo originates within the House Select Committee on Intelligence, I don’t think even President Trump could (or should) just decide to release it. Reportedly it reviews a lot of classified info about the FISA process, but the memo itself is an output of the House committee. The House needs to do so.... ASAP.
I would say the opposite led to this situation; an attempted bureaucratic coup detat. So regardless of the risk they all need TS clearances. All of them.