Help please

We were back to blue skies and sun today. We’d an exciting start to our walk when Brodie picked up a scent in the woods and bolted. I suspect he caught the scent of roe deer ( there are plenty about) - thankful the appeared again after 5 mins none the worse for his adventure.
I came across this attractive shrub next to a burn. Can anyone identify it? I wonder if it has seeded from a neighbouring garden rather than being a wildflower.