of this Current Report on Form 8-K (including Exhibit 99.1) is furnished and shall not be deemed “filed” for purposes of Section 18 of the Securities Exchange Act of 1934, as amended, or subject to the liabilities of that section or Sections 11 and 12(a)(2) of the Securities Act of 1933, as amended. The information shall not be deemed incorporated by reference into any other filing with the Securities and Exchange Commission made by the Company, whether made before or after today’s date, rega…

Entry into a Material Definitive Agreement. On October 13, 2026 (the “Effective Date”), Tenable Holdings, Inc. (the “Company”) entered into a credit agreement (the “Credit Agreement”) by and among the Company, as borrower, JPMorgan Chase Bank, N.A., as administrative agent (in such capacity, the “Administrative Agent”), collateral agent and L/C issuer, and the lenders from time to time party thereto (the “Lenders”). The Credit Agreement provides for a senior secured revolving credit facility…

Creation of a Direct Financial Obligation or an Obligation under an Off-Balance Sheet Arrangement of a Registrant. The information set forth under

Director — Charles Bell: The filing discloses the appointment of a new independent director to an expanded board, which is a routine governance action rather than an executive departure.

Other Events. Press Releases On September 10, 2026, the Company issued a press release announcing the proposed Offering. A copy of the press release is attached hereto as Exhibit 99.1 and incorporated herein by reference. On September 10, 2026, the Company issued a press release announcing the pricing of the Notes. A copy of the press release is attached hereto as Exhibit 99.2 and is incorporated herein by reference. Forward-Looking Statements Any statements made in this Current Report on For…

Creation of Direct Financial Obligation or an Obligation under an Off-Balance Sheet Arrangement or a Registrant. The information set forth under

Termination of a Material Definitive Agreement. The information set forth under

Entry into a Material Definitive Agreement. Indenture and Notes On September 15, 2026, Tenable Holdings, Inc. (the “Company”) completed its previously announced private offering (the “Offering”) of $800,000,000 aggregate principal amount of 0.25% Convertible Senior Notes due 2031 (the “Notes”), including the exercise in full of the initial purchasers’ option to purchase up to an additional $75,000,000 principal amount of the Notes. The Notes were issued pursuant to an indenture, dated Septemb…

Unregistered Sales of Equity Securities. The information set forth under

of this Current Report on Form 8-K (including Exhibit 99.1) is furnished and shall not be deemed “filed” for purposes of Section 18 of the Securities Exchange Act of 1934, as amended, or subject to the liabilities of that section or Sections 11 and 12(a)(2) of the Securities Act of 1933, as amended. The information shall not be deemed incorporated by reference into any other filing with the Securities and Exchange Commission made by the Company, whether made before or after today’s date, rega…

of this Current Report on Form 8-K (including Exhibit 99.1) is furnished and shall not be deemed “filed” for purposes of Section 18 of the Securities Exchange Act of 1934, as amended, or subject to the liabilities of that section or Sections 11 and 12(a)(2) of the Securities Act of 1933, as amended. The information shall not be deemed incorporated by reference into any other filing with the Securities and Exchange Commission made by the Company, whether made before or after today’s date, rega…

of this Current Report on 8-K (including Exhibit 99.1) is furnished and shall not be deemed “filed” for purposes of Section 18 of the Securities Exchange Act of 1934, as amended, or subject to the liabilities of that section or Sections 11 and 12(a)(2) of the Securities Act of 1933, as amended. The information shall not be deemed incorporated by reference into any other filing with the Securities and Exchange Commission made by the Company, whether made before or after today’s date, regardles…

Other Events. On January 15, 2026, the Company's Board of Directors approved an increase to the Company's existing share repurchase program of up to an additional $150 million, which is also announced in the press release furnished as Exhibit 99.1 to this report. Repurchases under the share repurchase program may be made in the open market, in privately negotiated transactions or in such other manner as determined by the Company, including through repurchase plans complying with the rules and…

of this Current Report on 8-K (including Exhibit 99.1) is furnished and shall not be deemed “filed” for purposes of Section 18 of the Securities Exchange Act of 1934, as amended, or subject to the liabilities of that section or Sections 11 and 12(a)(2) of the Securities Act of 1933, as amended. The information shall not be deemed incorporated by reference into any other filing with the Securities and Exchange Commission made by the Company, whether made before or after today’s date, regardles…

Chief Financial Officer — Matthew Brown: The Company appointed Matthew Brown as Chief Financial Officer, bringing in a new external hire with significant experience.

of this Current Report on 8-K (including Exhibit 99.1) is furnished and shall not be deemed “filed” for purposes of Section 18 of the Securities Exchange Act of 1934, as amended, or subject to the liabilities of that section or Sections 11 and 12(a)(2) of the Securities Act of 1933, as amended. The information shall not be deemed incorporated by reference into any other filing with the Securities and Exchange Commission made by the Company, whether made before or after today’s date, regardles…

Other Events. On July 28, 2025, the Company's Board of Directors approved an increase to the Company's existing share repurchase program of up to an additional $250 million, which is also announced in the press release furnished as Exhibit 99.1 to this report. Repurchases under the share repurchase program may be made in the open market, in privately negotiated transactions, or in such other manner as determined by the Company, including through repurchase plans complying with the rules and r…

Director — Stephen A. Vintz and Mark Thurmond: The Board of Directors appointed two new directors to the board.

of this Current Report on 8-K (including Exhibit 99.1) is furnished and shall not be deemed “filed” for purposes of Section 18 of the Securities Exchange Act of 1934, as amended, or subject to the liabilities of that section or Sections 11 and 12(a)(2) of the Securities Act of 1933, as amended. The information shall not be deemed incorporated by reference into any other filing with the Securities and Exchange Commission made by the Company, whether made before or after today’s date, regardles…

Co-Chief Executive Officers — Stephen A. Vintz and Mark Thurmond: Mr. Vintz and Mr. Thurmond were permanently appointed as co-Chief Executive Officers.

principal accounting officer — J. Barron Anschutz: Mr. Anschutz was promoted to principal accounting officer within the company.

Other Events. On February 7, 2025 , Ermetic Ltd., a company organized under the laws of the State of Israel (“Purchaser”) and an indirect, wholly owned subsidiary of Tenable, completed its previously announced acquisition (the “Acquisition”) of Vulcan Cyber Ltd., a company organized under the laws of the State of Israel (“Vulcan Cyber”). The Acquisition was effectuated pursuant to a Share Purchase Agreement, dated as of January 29, 2025 (the “SPA”) by and among Purchaser, Vulcan Cyber, each o…

of this Current Report on 8-K (including Exhibit 99.1) is furnished and shall not be deemed “filed” for purposes of Section 18 of the Securities Exchange Act of 1934, as amended, or subject to the liabilities of that section or Sections 11 and 12(a)(2) of the Securities Act of 1933, as amended. The information shall not be deemed incorporated by reference into any other filing with the Securities and Exchange Commission made by Tenable, whether made before or after today’s date, regardless of…

of this Current Report on 8-K (including Exhibit 99.1) is furnished and shall not be deemed “filed” for purposes of Section 18 of the Securities Exchange Act of 1934, as amended, or subject to the liabilities of that section or Sections 11 and 12(a)(2) of the Securities Act of 1933, as amended. The information shall not be deemed incorporated by reference into any other filing with the Securities and Exchange Commission made by the Company, whether made before or after today’s date, regardles…

of this Current Report on 8-K (including Exhibit 99.1) is furnished and shall not be deemed “filed” for purposes of Section 18 of the Securities Exchange Act of 1934, as amended (the “Exchange Act”), or subject to the liabilities of that section or Sections 11 and 12(a)(2) of the Securities Act of 1933, as amended. The information shall not be deemed incorporated by reference into any other filing with the Securities and Exchange Commission made by Tenable, whether made before or after today’…