X0306 4 2019-03-01 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 2019-03-01 4 S 0 2868 31.70 D 76306 I By Spouse Common Stock 2019-03-01 4 S 0 481 32.13 D 75825 I By Spouse Common Stock 2019-03-01 4 S 0 18538 31.70 D 677628 I By Trust Common Stock 2019-03-01 4 S 0 3113 32.13 D 674515 I By Trust Common Stock 2019-03-01 5 A 0 E 2173 19.55 A 2173 D Common Stock 2019-03-04 4 S 0 2525 30.85 D 73300 I By Spouse Common Stock 2019-03-04 4 S 0 295 31.70 D 73005 I By Spouse Common Stock 2019-03-04 4 S 0 16331 30.85 D 658184 I By Trust Common Stock 2019-03-04 4 S 0 1905 31.70 D 656279 I By Trust 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 $31.10 to $32.095 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 ranges set forth in footnotes (2), (3), (6) and (7) to this Form 4. The price reported in Column 4 is a weighted average price. These shares were sold in multiple transactions at prices ranging from $32.10 to $32.165 inclusive. 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. Mary Kathryn B. Huffard, John C. Huffard III, Samuel C. Huffard and Brown B. Huffard are the beneficiaries of this trust. These shares were acquired under the Issuer's Employee Stock Purchase Plan in transactions that were exempt under both Rule 16b-3(d) and Rule 16b-3(c). The price reported in Column 4 is a weighted average price. These shares were sold in multiple transactions at prices ranging from $30.34 to $31.33 inclusive. The price reported in Column 4 is a weighted average price. These shares were sold in multiple transactions at prices ranging from $31.34 to $32.04 inclusive. Mary Kathryn Braden Huffard and Jonathan M. Forster, as Trustees of The Three Suns Exempt Irrevocable Trust U/T/A dated March 2, 2012. Mary Kathryn B. Huffard, John C. Huffard III, Samuel C. Huffard and Brown B. Huffard are the beneficiaries of this trust. /s/ Brian F. Leaf, Attorney-in-Fact 2019-03-05