A U.S. District judge is scheduled to hear arguments on Wednesday in a closely watched case that is testing the bounds of attorney-client privilege against national security interests.

Judge Amit Mehta will weigh whether Washington, D.C.-headquartered firm Covington & Burling is required to turn over to the U.S. Securities and Exchange Commission the names of nearly 300 clients whose information may have been exposed in a 2020 cyberattack.