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

SECURITIESFORM AND EXCHANGE COMMISSION8-K

Washington,CURRENT D.C.REPORT 20549Pursuant to Section 13 or 15(d) of the Securities Exchange Act of 1934

~~FORM~~ July 8-K, 2026Date of Report (Date of Earliest Event Reported)

~~CURRENT~~Central ~~REPORT Pursuant~~Index toKey ~~Section~~Number 13of orthe ~~15(d)~~issuing ofentity: 0002061934 ~~the~~BMO ~~Securities~~2025-5C12 ~~Exchange~~Mortgage ~~Act~~Trust(Exact name of ~~1934~~issuing entity)

~~Date~~Central Index Key Number of ~~Report~~the registrant: 0001861132 BMO Commercial Mortgage Securities LLC(~~Date~~Exact name of ~~earliest~~registrant ~~event~~as ~~reported~~specified in its charter) ~~October 9,~~ ~~2025~~

~~BMO~~Central ~~2025-5C12~~Index ~~Mortgage~~Key ~~Trust~~Number of the sponsor: 0000927971 Bank of Montreal(Exact name of sponsor as specified in its charter)

Central Index Key Number of the sponsor: 0001968416 Argentic Real Estate Finance 2 LLC(Exact name of ~~issuing~~sponsor ~~entity~~as specified in its charter)

(Central Index Key ~~number~~Number of ~~issuing~~the ~~entity~~sponsor: 0001701238 ~~0002061934~~Citi Real Estate Funding Inc.(Exact name of sponsor as specified in its charter)

~~BMO~~Central ~~Commercial~~Index ~~Mortgage~~Key ~~Securities~~Number ~~LLC~~of the sponsor: 0001541294 German American Capital Corporation(Exact name of sponsor as specified in its charter)

Central Index Key Number of the sponsor: 0001089877 KeyBank National Association(Exact name of ~~the~~sponsor ~~depositor~~ as specified in its charter)

(Central Index Key ~~number~~Number of ~~depositor~~the sponsor: 0001548405 ~~0001861132~~Starwood Mortgage Capital LLC(Exact name of sponsor as specified in its charter)

~~Bank~~Central Index Key Number of ~~Montreal~~the sponsor: 0001685185 UBS AG(Exact name of sponsor as specified in its charter)

(Central Index Key ~~number~~Number of the sponsor: 0001931347 ~~0000927971~~Greystone Commercial Mortgage Capital LLC(Exact name of sponsor as specified in its charter)

~~Argentic~~Central Index Key Number of the sponsor: 0001542256 Natixis Real Estate ~~Finance~~Capital 2 LLC(Exact name of sponsor as specified in its charter)

(Central Index Key number: 000196841)

New York		333-280224-09		38-4369410 38-4369411
(State or other jurisdiction of incorporation of issuing entity)		(Commission File Number of issuing entity)		(I.R.S. Employer Identification Numbers)

~~Citi~~c/o ~~Real~~Computershare ~~Estate~~Trust ~~Funding~~Company, ~~Inc~~N.A.9062 Old Annapolis RoadColumbia, MD 21045(Address of principal executive offices of the issuing entity) (Zip Code)

(~~Central~~212) ~~Index~~885-4000Registrant's ~~Key~~Telephone number:, ~~0001701238)~~including area code

~~German~~Former ~~American~~name ~~Capital~~or ~~Corporation~~former address, if changed since last report: Not Applicable

~~(Central~~Check ~~Index~~the ~~Key~~appropriate ~~number:~~box ~~000154129)~~below if the Form 8-K filing is intended to simultaneously satisfy the filing obligation of the registrant under any of the following provisions:

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

~~(Central~~☐ Soliciting ~~Index~~material ~~Key~~pursuant ~~number:~~to ~~0001089877~~Rule 14a-12 under the Exchange Act (17 CFR 240.14a-12)

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

☐ Pre-commencement communications pursuant to Rule 13e-4(~~Central~~c) ~~Index~~under ~~Key~~the ~~number:~~Exchange ~~0001548405~~Act(17 CFR 240.13e-4(c))

~~UBS~~Securities AGregistered pursuant to Section 12(b) of the Act:

~~(Central~~Title ~~Index~~of ~~Key~~each ~~number:~~class ~~0001685185~~Trading Symbol(s) Name of each exchange on which registered

~~Greystone~~Indicate ~~Commercial~~by ~~Mortgage~~check ~~Capital~~mark ~~LLC~~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).

~~(Central~~☐ Emerging ~~Index~~growth ~~Key number: 0001931347)~~company

~~Natixis~~☐ If ~~Real~~an ~~Estate~~emerging ~~Capital~~growth ~~LLC~~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.

~~(Central~~Item ~~Index~~8.01 ~~Key~~Other ~~number: 0001542256)~~Events.

Reference is hereby made to the pooling and servicing agreement (~~Exact~~the ~~name~~“BMO 2025-5C12 PSA”) dated as of ~~sponsors~~October 1, 2025, relating to the BMO 2025-5C12 Mortgage Trust (the “Issuing Entity”). The BMO 2025-5C12 PSA was filed as ~~specified~~Exhibit 4.1 to the Current Report on Form 8-K/A with respect to the Issuing Entity, filed on October 9, 2025 under Commission File Number 333-280224-09. Capitalized terms used but not defined herein shall have the meanings assigned to them in ~~their~~the ~~charters)~~BMO 2025-5C12 PSA.

Delaware	333-280224-09	86-2713125
(State or other jurisdiction	(Commission File Number	(IRS Employer Identification
of incorporation of depositor)	of issuing entity)	No. of depositor)

The Mortgage Loans secured by the Mortgaged Properties identified on the Mortgage Loan Schedule as Warren Corporate Center and 1000 Portside Drive, each an asset of the Issuing Entity, are being serviced pursuant to the pooling and servicing agreement (the “Benchmark 2025-V17 PSA”), dated as of September 1, 2025, between Deutsche Mortgage & Asset Receiving Corporation, as depositor, Trimont LLC, as master servicer, Greystone Servicing Company LLC, as special servicer, Park Bridge Lender Services LLC, as operating advisor and as asset representations reviewer, and Computershare Trust Company, National Association, as trustee, certificate administrator, paying agent, and as custodian, which governs the issuance of the Benchmark 2025-V17 Mortgage Trust, Commercial Mortgage Pass-Through Certificates, Series 2025-V17. The Benchmark 2025-V17 PSA was filed as Exhibit 4.2 to the Current Report on Form 8-K with respect to the Issuing Entity, filed on September 23, 2025 under Commission File Number 333-280224-09.

151 West 42nd Street
New York, New York	10036
(Address of principal executive offices of depositor)	(Zip Code of depositor)

Effective as of July 8, 2026, the directing holder under the Benchmark 2025-V17 PSA has terminated Greystone Servicing Company LLC as special servicer under the Benchmark 2025-V17 PSA, and has appointed Torchlight Loan Services, LLC to act as successor special servicer under the Benchmark 2025-V17 PSA. A copy of the related Acknowledgement of Replacement Special Servicer dated July 8, 2026 is attached hereto as Exhibit 20.1.

~~Depositor’s~~Item ~~telephone~~9.01 ~~number,~~Financial ~~including~~Statements ~~area~~and ~~code (212) 885-4000~~ Exhibits.

~~Not Applicable~~(d) Exhibits

~~(Former~~Exhibit ~~name or former address, if changed since last report~~No.) Description

~~Check~~Exhibit ~~the appropriate box below if the Form 8-K filing~~20.1 isAcknowledgement ~~intended to simultaneously satisfy the filing obligation~~ of ~~the~~Replacement ~~registrant~~Special ~~under~~Servicer, ~~any~~dated ofJuly ~~the~~8, ~~following provisions:~~2026

~~[ ] Written~~SIGNATURES ~~communications pursuant to Rule 425 under the Securities Act (17 CFR 230.425)~~

~~[ ] Soliciting~~Pursuant ~~material~~to ~~pursuant~~the torequirements ~~Rule 14a-12 under~~of the Securities Exchange Act ~~(17~~of ~~CFR~~1934, ~~240~~the registrant has duly caused this report to be signed on its behalf by the undersigned hereunto duly authorized.~~14a-12)~~

~~[ ] Pre-commencement~~BMO ~~communications~~Commercial ~~pursuant to~~Mortgage ~~Rule 14d-2(b)~~Securities ~~under the Exchange Act~~ LLC(~~17 CFR 240.14d-2(b~~Depositor))

~~[ ] Pre-commencement~~/s/ ~~communications~~Paul ~~pursuant to~~VanderslicePaul ~~Rule 13e-4(c)~~Vanderslice, ~~under~~Chief ~~the~~Executive ~~Exchange Act (17 CFR 240.13e-4(c))~~Officer

~~Securities~~Date: July ~~registered~~8, ~~pursuant to Section 12(b) of the Act:~~2026

Title of each class Trading Symbol(s) Name of each exchange on which registered None

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 October 9, 2025 (the “Closing Date”), BMO Commercial Mortgage Securities LLC (the “Depositor”) caused the issuance, pursuant to a Pooling and Servicing Agreement, dated as of October 1, 2025 (the “Pooling and Servicing Agreement”), between the Depositor, as depositor, Midland Loan Services, a Division of PNC Bank, National Association, as master servicer, Argentic Services Company LP, as special servicer, Park Bridge Lender Services LLC, as operating advisor and as asset representations reviewer, Computershare Trust Company, National Association, as certificate administrator and as trustee, of the BMO 2025-5C12 Mortgage Trust, Commercial Mortgage Pass-Through Certificates, Series 2025-5C12 (the “Certificates”). Capitalized terms used but not defined herein shall have the meanings assigned to them in the Pooling and Servicing Agreement. The Pooling and Servicing Agreement was attached as Exhibit 4.1 to the Depositor’s Current Report on Form 8-K/A, filed with the Securities and Exchange Commission (the “Commission”) on October 9, 2025 under Commission File No. 333-280224-09.

The Certificates consist of the following classes, designated as (i) the Class A-1, Class A-2, Class A-3, Class X-A, Class X-B, Class A-S, Class B and Class C Certificates (collectively, the “Public Certificates”) and (ii) the Class X-D, Class X-F, Class D, Class E, Class F, Class G-RR, Class J-RR and Class R Certificates (collectively, the “Private Certificates”).

All of the Public Certificates, having an aggregate initial principal amount of $556,413,000, were sold to BMO Capital Markets Corp. (“BMO Capital Markets”), Citigroup Global Markets Inc. (“CGMI”), Deutsche Bank Securities Inc. (“DBSI”), KeyBanc Capital Markets Inc. (“KeyBanc Capital”), UBS Securities LLC (“UBS Securities”), Academy Securities, Inc. (“Academy”), Bancroft Capital, LLC (“Bancroft”), Drexel Hamilton, LLC (“Drexel”), Mischler Financial Group, Inc. (“Mischler”) and Natixis Securities Americas LLC (“Natixis” and, together with BMO Capital Markets, CGMI, DBSI, KeyBanc Capital, UBS Securities, Academy, Bancroft, Drexel and Mischler, in such capacity, the “Underwriters”), pursuant to an Underwriting Agreement, dated as of September 19, 2025 (the “Underwriting Agreement”), between the Depositor and the Underwriters. BMO Capital, CGMI, DBSI, KeyBanc Capital and UBS Securities are acting as co-lead managers in connection with the offering of the Public Certificates. The Public Certificates were offered by the Underwriters for sale to the public, pursuant to the Depositor’s Preliminary Prospectus, dated September 15, 2025, and by the Prospectus, dated September 19, 2025 (the “Prospectus”), in negotiated transactions or otherwise at varying prices determined at the time of sale. In connection with the issuance, and sale to the Underwriters, of the Public Certificates, a legal opinion was rendered related to the validity of, and certain federal income tax considerations relating to, the Public Certificates, which legal opinion is attached hereto as Exhibit 5. The Prospectus was filed with the Commission on September 23, 2025 under Commission File Number 333-280224-09.

All of the Private Certificates, having an aggregate initial principal amount of $71,799,000 were sold to BMO Capital Markets, CGMI, DBSI, KeyBanc Capital, UBS Securities, Academy, Bancroft, Drexel, Mischler and Natixis (together with BMO Capital Markets, CGMI, DBSI, KeyBanc Capital, UBS Securities, Academy, Bancroft, Drexel and Mischler, in such capacity, the “Initial Purchasers”), pursuant to a Purchase Agreement, dated as of September 19, 2025, between the Depositor and the Initial Purchasers. The Private Certificates were sold in private placement transactions exempt from registration under the Securities Act of 1933, as amended (the “Act”), pursuant to Section 4(a)(2) of the Act.

The net proceeds of the sale of the Certificates were applied to the purchase of the Mortgage Loans by the Depositor from Bank of Montreal, Argentic Real Estate Finance 2 LLC (“AREF2”), Citi Real Estate Funding Inc., German American Capital Corporation, Greystone Commercial Mortgage Capital LLC, KeyBank National Association, Natixis Real Estate Capital LLC, Starwood Mortgage Capital, LLC and UBS AG New York Branch. The net proceeds to the Depositor of the offering of the Certificates, after

deducting expenses payable by the Depositor in connection with the issuance and distribution of the Certificates of approximately $7,815,950.06, were approximately $653,525,207.05. Of the expenses paid by the Depositor, approximately $311,545.00 were paid directly to affiliates of the Depositor, $80,000,00 in the form of fees were paid to the Underwriters and the Initial Purchasers, $124,845.00 were paid to or for the counsel to the Underwriters and the Initial Purchasers, and approximately $7,299,560.06 were other expenses. All of the foregoing expense amounts are the Depositor’s reasonable estimates of such expenses. No underwriting discounts and commissions or finder’s fees were paid by the Depositor.

Further information regarding sales of the Public Certificates is set forth in the Underwriting Agreement (including, as to the price per class of Public Certificates, on Schedule II thereto) attached as Exhibit 1 to the Depositor’s Current Report on Form 8-K/A, filed with the Commission on October 9, 2025 under Commission File No. 333-280224-09, and in the Prospectus. The related registration statement (file no. 333-280224) was originally declared effective on October 10, 2024.

AREF2, in its capacity as “retaining sponsor” (as such term is defined in Regulation RR (17 C.F.R. Part 246) promulgated under Section 15G of the Securities Exchange Act of 1934, as amended (“Regulation RR”)) (the “Retaining Sponsor”), is satisfying its credit risk retention obligation under Regulation RR in connection with the securitization of the Mortgage Loans referred to above by (i) the purchase by Argentic Securities Holdings 2 Cayman Limited (the “Argentic MOA”), a “majority-owned affiliate” (as defined in Regulation RR) of AREF2, on the Closing Date, of an “eligible vertical interest” (as defined in Regulation RR), in the form of Certificates representing at least 2.4000% of the Certificate Balance or Notional Amount, as applicable, of each Class of Certificates (other than the Class R Certificates) (collectively, the “VRR Interest”), which VRR Interest also represents approximately 2.4007% of all the “ABS interests” (i.e., the sum of the aggregate initial Certificate Balances of all Classes of Certificates (other than the Class R Certificates)) issued by the issuing entity in connection with this securitization transaction, and (ii) the purchase by the Argentic MOA, on the Closing Date, of an “eligible horizontal residual interest” (as defined in Regulation RR) consisting of the Class G-RR and Class J-RR Certificates (collectively, the “HRR Certificates”) (in each case excluding the portion of such Class comprising the VRR Interest), with an aggregate initial Certificate Balance of $36,594,000, and having an aggregate fair value representing approximately 2.6758% of the fair value, as of the Closing Date, of all of the Certificates (other than the Class R Certificates) as of the Closing Date, determined in accordance with Generally Accepted Accounting Principles.

The aggregate fair value, as of the Closing Date, of the HRR Certificates (excluding in the case of each Class comprising the HRR Certificates, the portion thereof comprising the VRR Interest) is equal to approximately $17,695,870, representing approximately 2.6758% of the aggregate fair value, as of the Closing Date, of all the Certificates (other than the Class R Certificates) issued by the issuing entity.

The aggregate fair value, as of the Closing Date, of the “eligible horizontal residual interest” (as defined in Regulation RR) that the Retaining Sponsor would be required to retain in order to meet the credit risk retention requirements of Regulation RR with respect to this securitization transaction, if it was relying solely on an “eligible horizontal residual interest” to satisfy such requirements, is approximately $33,067,058, representing 5% of the aggregate fair value, as of the Closing Date, of all of the Certificates (other than the Class R Certificates) issued by the issuing entity.

Item 9.01. Financial Statements and Exhibits.

(d) Exhibits

Exhibit No.	Description
Exhibit 5	Legality Opinion of Orrick, Herrington & Sutcliffe LLP, dated October 9, 2025
Exhibit 8	Tax Opinion of Orrick, Herrington & Sutcliffe LLP, dated October 9, 2025 (included as part of Exhibit 5)
Exhibit 23	Consent Opinion of Orrick, Herrington & Sutcliffe LLP, dated October 9, 2025 (included as part of Exhibit 5)

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.

Date: October 9, 2025	BMO COMMERCIAL MORTGAGE SECURITIES LLC
	By:	/s/ Paul Vanderslice
		Name:	Paul Vanderslice
		Title:	Chief Executive Officer

BMO 2025-5C12 – Form 8-K (Closing)

Filing Compare · BMO 2025-5C12 Mortgage Trust