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

September 24, 2025
Date of Report (Date of Earliest Event Reported)

Central Index Key Number of the issuing entity: 0001693368
CD 2017-CD3 Mortgage Trust
(Exact name of issuing entity)

Central Index Key Number of the registrant: 0001258361
Citigroup Commercial Mortgage Securities Inc.
(Exact name of registrant as specified in its charter)

Central Index Key Number of the sponsor: 0001541001
Citigroup Global Markets Realty Corp.
(Exact name of sponsor as specified in its charter)

Central Index Key Number of the sponsor: 0001541294
German American Capital Corporation
(Exact name of sponsor as specified in its charter)

New York		333-207132-10		38-4021846 38-4021847 38-7170532
(State or other jurisdiction of incorporation of issuing entity)		(Commission File Number of issuing entity)		(I.R.S. Employer Identification Numbers)

c/o Computershare Trust Company, N.A., as agent for
Wells Fargo Bank, National Association
9062 Old Annapolis Road
Columbia, MD 21045
(Address of principal executive offices of the issuing entity) (Zip Code)

(212) 816-5343
Registrant's Telephone number, including area code

Former name or former address, if changed since last report: Not Applicable

Check the appropriate box below if the Form 8-K filing is intended to simultaneously satisfy the filing obligation 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

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.

Computershare Trust Company, N.A., as agent for Wells Fargo Bank, National Association, as certificate administrator (the “Certificate Administrator”), made distributions to the Certificateholders on the September 12, 2025 distribution date. The Certificate Administrator was subsequently notified by Midland Loan Services, a Division of PNC Bank, National Association, as master servicer (the “Master Servicer”), on September 24, 2025 of a revision to its September 2025 reporting due to losses that were not originally reported, resulting in an overpayment to class A-AB and the VRR Interest in the, amounts of $873,501.46 and $16,917.97 respectively. The Certificate Administrator has submitted a claim to reclaim the overpayments.

SIGNATURES

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.

Citigroup Commercial Mortgage Securities Inc.
(Depositor)

/s/ Richard Simpson
Richard Simpson, President

Date: September 30, 2025

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

UNITED STATES
SECURITIES AND EXCHANGE COMMISSION
Washington D.C. 20549

CURRENT REPORT
Pursuant to Section 13 or 15(d) of the Securities Exchange Act of 1934

CD 2017-CD3 Mortgage Trust 8-K