From the link below:

Under normal conditions, the President of the United States is required by Title 50 U.S.C. § 3091(a)(1) to "ensure that the congressional intelligence committees are kept fully and currently informed of the intelligence activities of the United States, including any significant anticipated intelligence activity as required by [the] title." However, under "extraordinary circumstances", when the President thinks "it is essential to limit access" to information about a covert action, 50 U.S.C. § 3093(c)(2) allows the President to limit reporting to the Gang of Eight.