8-K

Date: August 6, 2026

A10 NETWORKS, INC.

/s/ Scott Weber

Scott Weber

General Counsel

UNITED STATES

SECURITIES AND EXCHANGE COMMISSION

Washington, D.C. 20549

FORM 8-K

CURRENT REPORT

Pursuant to Section 13 or 15(d)

of The Securities Exchange Act of 1934

Date of Report (Date of earliest event reported): August 6, 2026

A10 NETWORKS, INC.

(Exact name of registrant as specified in its charter)

Delaware

001-36343

20-1446869

(State or Other Jurisdiction

of Incorporation)

(Commission

File Number)

(I.R.S. Employer

Identification No.)


2300 Orchard Parkway
San Jose, CA		95131
(Address of principal executive offices)		(Zip Code)

(408) 325-8668

(Registrant’s telephone number, including area code)

N/A

(Former name or former address, if changed since last report.)

Check the appropriate box below if the Form 8-K filing is intended to simultaneously satisfy the filing obligations of the registrant under any of the following provisions:

☐	Written communications pursuant to Rule 425 under the Securities Act (17 CFR 230.425)

☐	Soliciting material pursuant to Rule 14a-12 under the Exchange Act (17 CFR 240.14a-12)

☐	Pre-commencement communications pursuant to Rule 14d-2(b) under the Exchange Act (17 CFR 240.14d-2(b))

☐	Pre-commencement communications pursuant to Rule 13e-4(c) under the Exchange Act (17 CFR 240-13e-4(c))

Securities registered pursuant to Section 12(b) of the Act:

Title of each class

Trading

symbol(s)

Name of each exchange

on which registered

Common Stock, $0.00001 par value

ATEN

New York Stock Exchange

Indicate by check mark whether the registrant is an emerging growth company as defined in Rule 405 of the Securities Act of 1933 (§ 230.405 of this chapter) or Rule 12b-2 of the Securities Exchange Act of 1934 (§240.12b-2 of this chapter).

Emerging growth 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. ☐

Item 8.01

Other Events.

On August 6, 2026, A10 Networks, Inc. filed a prospectus supplement to its automatic shelf registration statement on Form S-3 (Registration No. 333-298099) with the Securities and Exchange Commission. This Current Report on Form 8-K is being filed solely for the purpose of filing the opinion of Pillsbury Winthrop Shaw Pittman LLP relating to the legality of the issuance and sale of the securities set forth in the prospectus supplement, which opinion is attached as Exhibit 5.1 hereto.

Item 9.01

Financial Statements and Exhibits.

(d) Exhibits


Exhibit		Description

5.1		Opinion of Pillsbury Winthrop Shaw Pittman LLP.

23.1		Consent of Pillsbury Winthrop Shaw Pittman LLP (included in Exhibit 5.1).

104.1		Cover Page Interactive Data File (embedded within the inline XBRL document).

SIGNATURE

Pursuant to the requirements of the Securities Exchange Act of 1934, the registrant has duly caused this report to be signed on its behalf by the undersigned hereunto duly authorized.