X0306 4/A 2019-12-16 2019-12-18 1 0001660280 Tenable Holdings, Inc. TENB 0001601528 Accel Growth Fund III L.P. 500 UNIVERSITY AVENUE PALO ALTO CA 94301 0 0 1 0 0001630897 Accel Growth Fund Investors 2014 L.L.C. 500 UNIVERSITY AVENUE PALO ALTO CA 94301 0 0 1 0 0001601529 Accel Growth Fund III Associates L.L.C. 500 UNIVERSITY AVENUE PALO ALTO CA 94301 0 0 1 0 0001605863 Accel Growth Fund III Strategic Partners L.P. 500 UNIVERSITY AVENUE PALO ALTO CA 94301 0 0 1 0 Common Stock 2019-12-16 4 J 0 2694300 0.00 D 4326710 D Common Stock 2019-12-16 4 J 0 127200 0.00 D 204267 I By Accel Growth Fund III Strategic Partners L.P. Common Stock 2019-12-16 4 J 0 178500 0.00 D 286648 I By Accel Growth Fund Investors 2014 L.L.C. On December 16, 2019, Accel Growth Fund III L.P. distributed, for no consideration, 2,694,300 shares of common stock of the Issuer (the "Accel III Shares") to its limited partners and to Accel Growth Fund III Associates L.L.C. ("Accel III GP"), the general partner of Accel Growth Fund III L.P., representing each such partner's pro rata interest in such Accel III Shares. On the same date, Accel III GP distributed, for no consideration, the Accel III Shares it received in the distribution by Accel Growth Fund III L.P. to its members, representing each such member's pro rata interest in such Accel III Shares. All of the aforementioned distributions were made in accordance with the exemptions afforded by Rules 16a-13 and 16a-9 of the Securities Exchange Act of 1934, as amended. These shares are held by Accel Growth Fund III L.P. Accel III GP is the general partner of each of Accel Growth Fund III L.P. and Accel Growth Fund III Strategic Partners L.P. (together, the "Accel III Entities"). Accel III GP has sole voting and dispositive power with regard to the shares held by the Accel III Entities. Accel III GP disclaims Section 16 beneficial ownership over the securities reported herein except to the extent of its pecuniary interest therein, if any, and this report shall not be deemed an admission that such reporting person is the beneficial owner of such securities for Section 16 or any other purpose. On December 16, 2019, Accel Growth Fund III Strategic Partners L.P. distributed, for no consideration, 127,200 shares of common stock of the Issuer (the "Accel Strategic III Shares") to its limited partners and to Accel III GP, the general partner of Accel Growth Fund III Strategic Partners L.P., representing each such partner's pro rata interest in such Accel Strategic III Shares. On the same date, Accel III GP distributed, for no consideration, the Accel Strategic III Shares it received in the distribution by Accel Growth Fund III Strategic Partners L.P. to its members, representing each such member's pro rata interest in such Accel Strategic III Shares. All of the aforementioned distributions were made in accordance with the exemptions afforded by Rules 16a-13 and 16a-9 of the Securities Exchange Act of 1934, as amended. These shares are held by Accel Growth Fund III Strategic Partners L.P. Accel III GP disclaims Section 16 beneficial ownership over the securities reported herein except to the extent of its pecuniary interest therein, if any, and this report shall not be deemed an admission that such reporting person is the beneficial owner of such securities for Section 16 or any other purpose. On December 16, 2019, Accel Growth Fund Investors 2014 L.L.C. distributed, for no consideration, 178,500 shares of common stock of the Issuer (the "Accel 2014 Shares") to its members, representing each such member's pro rata interest in such Accel 2014 Shares. All of the aforementioned distributions were made in accordance with the exemptions afforded by Rules 16a-13 and 16a-9 of the Securities Exchange Act of 1934, as amended. These shares are held by Accel Growth Fund Investors 2014 L.L.C. Accel Growth Fund II Strategic Partners L.P. was inadvertently listed as a Reporting Person on the original Form 4. This amendment is being filed to remove Accel Growth Fund II Strategic Partners L.P. from the filing and to add Accel Growth Fund III Strategic Partners L.P. as a Reporting Person. /s/ Tracy L. Sedlock, as Attorney-in-Fact, for Accel Growth Fund III L.P. 2019-12-18 /s/ Tracy L. Sedlock, as Attorney-in-Fact, for Accel Growth Fund Investors 2014 L.L.C. 2019-12-18 /s/ Tracy L. Sedlock, as Attorney-in-Fact, for Accel Growth Fund III Associates L.L.C. 2019-12-18 /s/ Tracy L. Sedlock, as Attorney-in-Fact, for Accel Growth Fund III Strategic Partners L.P. 2019-12-18