X0306 4 2020-05-20 0 0001660280 Tenable Holdings, Inc. TENB 0001747310 Riddick Stephen A C/O TENABLE HOLDINGS, INC. 7021 COLUMBIA GATEWAY DRIVE, SUITE 500 COLUMBIA MD 21046 0 1 0 0 General Counsel & Secretary Common Stock 2020-05-20 4 M 0 2990 0 A 10193 D Common Stock 2020-05-21 4 S 0 1457 29.18 D 8736 D Restricted Stock Units 2020-05-20 4 M 0 2990 0 D Common Stock 2990.0 32895 D Each restricted stock unit ("RSU") represents a contingent right to receive one share of Issuer common stock. The sale reported on this Form 4 represents shares required to be sold by the Reporting Person to cover tax withholding obligations in connection with the vesting of restricted stock units. The sale occurred automatically to satisfy the tax withholding obligations to be funded by a "sell to cover" transaction and does not represent a discretionary trade by the Reporting Person. 25% of the shares underlying the RSUs granted on February 20, 2019, vested on May 20, 2020, and the remainder vest in equal quarterly installments over three years, subject to the Reporting Person's continuous service with the Issuer as of the applicable vesting date, and subject to acceleration in specified circumstances. /s/ David Bartholomew, Attorney-in-Fact 2020-05-22