Quarterly Report Pursuant to Section 13 or 15(d) of the Securities Exchange Act of 1934 For the Quarterly Period Ended March 31, 2026or ☐Transition Report Pursuant to Section 13 or 15(d) of the Securities Exchange Act of 1934 For the transition period from _____ to _____Commission file number 001-38600__________________ TENABLE HOLDINGS, INC. (Exact name of registrant as specified in its charter)__________________ Delaware 47-5580846 (State or other jurisdiction of incorporation or organization)(I.R.S. Employer Identification Number) 6100 Merriweather Drive, Columbia, Maryland 21044(Address of principal executive offices, including zip code)(410) 872-0555(Registrant’s telephone number, including area code)__________________ Securities registered pursuant to Section 12(b) of the Act: Title of each classTrading Symbol(s)Name of each exchange on which registeredCommon Stock, par value $0.01 per shareTENBThe Nasdaq Stock Market LLC Indicate by check mark whether the Registrant (1)has filed all reports required to be filed by Section13 or 15(d) of the SecuritiesExchange Act of 1934 during the preceding 12 months (or for such shorter period that the Registrant was required to file such reports),and (2)has been subject to such filing requirements for the past 90 days.Yes☒No☐ Indicate by check mark whether the registrant has submitted electronically every Interactive Data File required to be submitted pursuantto Rule 405 of Regulation S-T during the preceding 12 months (or for such shorter period that the registrant was required to submit suchfiles).Yes☒No☐ Indicate by check mark whether the registrant is a large accelerated filer, an accelerated filer, a non-accelerated filer, a smaller reportingcompany or an emerging growth company. See the definitions of “large accelerated filer,” “accelerated filer,” “smaller reportingcompany” and "emerging growth company" in Rule 12b-2 of the Exchange Act. Large accelerated filer☒Accelerated filer☐Non-accelerated filer☐Emerging growth company☐Smaller reporting company☐ If an emerging growth company, indicate by check mark if the registrant has elected not to use the extended transition period for complying with any new or revised financial accounting standards provided pursuant to Section 13(a) of the Exchange Act.☐ The number of shares of the Registrant's common stock outstanding as of April30, 2026 was 110,271,973. TENABLE HOLDINGS, INC.TABLE OF CONTENTS PART I – FINANCIAL INFORMATION Item 1.Financial StatementsConsolidated Balance SheetsConsolidated Statements of OperationsConsolidated Statements of Comprehensive Income (Loss)Consolidated Statements of Stockholders' EquityConsolidated Statements of Cash FlowsNotes to Consolidated Financial Statements1. Business and Summary of Significant Accounting Policies2. Revenue3. Cash Equivalents, Short-Term Investments and Other Investments4. Property and Equipment, Net5. Goodwill and Intangible Assets6. Leases7. Debt8. Commitments and Contingencies9. Stock-Based Compensation10. Income Taxes11. Net Earnings (Loss) Per Share Item 2.Management’s Discussion and Analysis of Financial Condition and Results of OperationsItem 3.Quantitative and Qualitative Disclosures About Market RiskItem 4.Controls and Procedures Item 1.Legal ProceedingsItem 1A.Risk FactorsItem 2.Unregistered Sales of Equity Securities and Issuer Purchases of Equity SecuritiesItem 6.ExhibitsSignatures Where You Can Find More Information Investors and others should note that we may announce material business and financial information to our investorsusing our investor relations website (https://investors.tenable.com), our filings with the Securities and ExchangeCommission (SEC), our website, webcasts, press releases, and conference calls. We use these mediums, including ourwebsite, to communicate with investors and the general public about our company, our products, and other issues, and forcomplying with our disclosure obligations under Regulation FD. It is possible that the information that we make availableon our website may be deemed to be material information. We therefore encourage investors and others interested in ourcompany to review the information that we make available on our website, in addition to following our SEC filings, ourwebcasts, press releases, and conference calls. The information we post through these channels is not a part of thisQuarterly Report on Form 10-Q. These channels may be updated from time to time on our investor relations website. TENABLE HOLDINGS, INC.CONSOLIDATED STATEMENTS OF OPERATIONS(Unaudited) TENABLE HOLDINGS, INC.CONSOLIDATED STATEMENTS OF COMPREHENSIVE INCOME (LOSS)(Unaudited) Three Months Ended March 31,(in thousands)20262025Net income (loss)$1,414$(22,935)Other comprehensive (loss) income, net of tax:Unrealized (losses) gains on available-for-sale securities, net(494)10Other comprehensive (loss) income(494)10Comprehensive income (loss)$920$(22,925) TENABLE HOLDINGS, INC.CONSOLIDATED STATEMENTS OF