Yes.
In addition to being rear-fanged venomous and having caused documented human fatalities from bites, Rhabdophis Tigrinus secretes a poison from it's nuchal glands. The poison is sequestered from toxins ingested from the toads they eat.
Diadophis punctatus (ringneck snakes) also secrete a poison from their cloaca. Animals ingesting it can become very ill. Last I heard, studies were still being performed regarding the toxicity of these secretions.