X0306 4 2019-02-27 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 2019-02-26 5 J 0 E 178253 0.00 D 702814 I By Trust Common Stock 2019-02-26 5 J 0 E 178253 0.00 A 3294982 I By Trust Common Stock 2019-02-27 4 S 0 1030 31.66 D 79174 I By Spouse Common Stock 2019-02-27 4 S 0 6648 31.66 D 696166 I By Trust Represents a transfer, and not a purchase or sale of securities, from 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 to Mary Kathryn Braden Huffard and Jonathan M. Forster, as Trustees of The Three Suns Exempt Irrevocable Trust U/T/A dated March 2, 2012, for no consideration. 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. 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. 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 $31.49 to $31.75 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 (5) to this Form 4. /s/ Brian F. Leaf, Attorney-in-Fact 2019-03-01