144 0001197652 XXXXXXXX LIVE 0001660280 Tenable Holdings, Inc. 001-38600 6100 MERRIWEATHER DRIVE COLUMBIA MD 21044 410-872-0555 SEAWELL A BROOKE Director Common Fidelity Brokerage Services LLC

900 Salem Street Smithfield RI 02917

115000 2854661.67 119344266 12/15/2025 NASDAQ Common 12/15/2025 Options Granted - 10/26/2017 Issuer N 115000 12/15/2025 Cash Y Today's sale took place in the Rosemary & A Brooke Seawell Rev Tr (Admin Trust) account in which A. Brooke Seawell is Trustee. 12/15/2025 /s/ Gerardo Ibarra-Munoz, as a duly authorized representative of Fidelity Brokerage Services LLC, as attorney-in-fact for Alexander B. Seawell