X0306 4 2019-07-26 0 0001660280 Tenable Holdings, Inc. TENB 0001747299 Huffard John C Jr C/O TENABLE HOLDINGS, INC. 7021 COLUMBIA GATEWAY DRIVE, SUITE 500 COLUMBIA MD 21046 1 0 0 0 Common Stock 2019-07-26 4 S 0 2090 31.73 D 50352 I By Spouse Common Stock 2019-07-26 4 S 0 13510 31.73 D 509828 I By Trust Common Stock 2173 D Common Stock 3294982 I By Trust The sales reported in this Form 4 were effected by the Reporting Person's spouse and Mary Kathryn Braden Huffard and Jonathan M. Forster, as Trustees of The Three Suns Non-Exempt Irrevocable Trust U/T/A dated March 2, 2012, as applicable, pursuant to Rule 10b5-1 trading plans. The price reported in Column 4 is a weighted average price. These shares were sold in multiple transactions at prices ranging from $31.50 to $31.99 inclusive. The Reporting Person undertakes to provide to the Issuer, any security holder of the Issuer, or the staff of the Securities and Exchange Commission, upon request, full information regarding the number of shares sold at each separate price within the range set forth in this footnote to this Form 4. Mary Kathryn Braden Huffard and Jonathan M. Forster, as Trustees of The Three Suns Non-Exempt Irrevocable Trust U/T/A dated March 2, 2012. The Reporting Person's spouse and children are the beneficiaries of this trust. Mary Kathryn Braden Huffard and Jonathan M. Forster, as Trustees of The Three Suns Exempt Irrevocable Trust U/T/A dated March 2, 2012. The Reporting Person's spouse and children are the beneficiaries of this trust. /s/ Brian F. Leaf, Attorney-in-Fact 2019-07-30