The rumors going around came from Super Luchas Magazine, a usually reputable publication from Mexico. It reports that Randy Orton violated the WWE Wellness Policy after testing positive for Dianabol and marijuana.
Marijuana isn't punishable by suspension in WWE, just a $2,500 fine. The report states that Orton tested positive for marijuana, was fined and then tested again for other substances where he tested positive for use of Dianabol. Dianabol (methandrostenolone) is an orally-effective anabolic steroid. Dianabol was commonly used by bodybuilders until Congress banned it under the Controlled Substances Act.
There is no confirmation to this rumor yet so take it for what it's worth.