Nope, that's not lens flare you're seeing. That's a solar flare — an insanely large, extremely bright solar flare.
NASA's Solar Dynamics Observatory caught the footage of the strongest flare we've seen yet this year last night. According to the Space Weather Prediction Center, the flare was strong enough to temporarily send them into a radio blackout, but, since the eruption was aimed away from Earth, it's unlikely that we'll see much geomagnetic interference from it right now. It should, however, rotate into a position closer to us over the next week, so we could still see some pretty impressive aurora-action yet.
You can also look at the very beginnings of the flare in all the different spectrums of color captured by the observatory if you like, which I think you will.
Images: NASA / SDO