Probably not. It sounds like the landlord is aware that you are in the property and has authorized you to live there as a co-tenant but has not required you to co-sign or guaranty the debt of the lease contract.
That being said, if rent is not paid, the landlord always has the right to evict you and all other occupants. But should that happen, the landlord should only be entitled to a possession judgment as to you. The landlord can take a money judgment (for unpaid rent) as to the tenant who is a party to the lease contract.
The above comment is meant as general advice. More information would be needed at a confidential consultation in order to provide an accurate evaluation of your legal options.