Yes, there is a real risk, even if it may be small once everything is fully dry. Salt water can leave conductive residue and ongoing corrosion inside a lens, especially around the mount contacts, aperture/focus circuitry, and motor power lines. In the worst case, shorts between power and signal contacts could potentially damage the camera body.

The bigger issue is that salt-water damage is often unstable: a device may seem fine briefly, then fail later as corrosion continues. That’s why repairers often treat confirmed salt-water exposure as beyond economical repair.

Practical advice: don’t test it on a new body if you’re risk-averse. If the lens shows any internal haze, residue, corrosion, or other signs that salt got inside, it’s likely not worth testing anyway. If you really want to check it, the safer approach is to try it only on a cheap sacrificial compatible body, not your new camera.