SEC Form DEFA14A filed by Curbline Properties Corp.

UNITED STATES

SECURITIES AND EXCHANGE COMMISSION

Washington, D.C. 20549

SCHEDULE 14A

(RULE 14a-101)

INFORMATION REQUIRED IN PROXY STATEMENT

SCHEDULE 14A INFORMATION

Proxy Statement Pursuant to Section 14(a) of the

Securities Exchange Act of 1934

Filed by the Registrant ☒ Filed by a Party other than the Registrant ☐

Check the appropriate box:

Curbline Properties Corp.

(Name of Registrant as Specified in Its Charter)

(Name of Person(s) Filing Proxy Statement, if Other Than the Registrant)

Payment of Filing Fee (Check all boxes that apply):

CURBLINE VOTE C 1234567890 000001 ENDORSEMENT_LINE_SACKPACKSACKPACK MRA SAMPLE DESIGNATION (IF ANY) ADD 1 ADD 2 ADD 3 ADD 4 ADD 5 ADD 6 Online Go to www.investorvote.com/curb or scan the QR code — login details are located in the shaded bar below. Phone Call toll free 1-800-652-VOTE (8683) within the USA, US territories and Canada Stockholder Meeting Notice 1234 5678 9012 345 Important Notice Regarding the Availability of Proxy Materials for the Curbline Properties Corp. Stockholder Meeting to be Held on May 7, 2026 Under Securities and Exchange Commission rules, you are receiving this notice that the proxy materials for the annual stockholders’ meeting are available on the Internet. Follow the instructions below to view the materials and vote online or request a copy. The items to be voted on and location of the annual meeting are on the reverse side. Your vote is important! This communication presents only an overview of the more complete proxy materials that are available to you on the Internet. We encourage you to access and review all of the important information contained in the proxy materials before voting. The Proxy Statement and 2025 Annual Report to Stockholders are available at: www.proxydocs.com/curb. www.investorvote.com/curbEasy Online Access — View your proxy materials and vote. Step 1: Go to www.investorvote.com/curb. Step 2: Click on the icon on the right to view meeting materials. Step 3: Return to the investorvote.com window and follow the instructions on the screen to log in. Step 4: Make your selections as instructed on each screen for your delivery preferences. Step 5: Vote your shares. When you go online, you can also help the environment by consenting to receive electronic delivery of future materials. Obtaining a Copy of the Proxy Materials – If you want to receive a copy of the proxy materials, you must request one. There is no charge to you for requesting a copy. Please make your request as instructed on the reverse side on or before April 27, 2026 to facilitate timely delivery. 2NOT COY 0485GB +

Stockholder Meeting Notice Curbline Properties Corp.’s Annual Meeting of Stockholders will be held virtually on Thursday, May 7, 2026 at 10:00 am ET, via live webcast at www.meetnow.global/MX2X6KG. Proposals to be voted on at the meeting are listed below along with the Board of Directors’ recommendations. The Board of Directors recommends a vote FOR all the director nominees listed, FOR Proposals 2 and 4 and for every 1 YEAR on Proposal 3: 1. Election of two Class II Directors: 01 - Jane E. DeFlorio 02 - Barry A. Sholem 2. Approval, on an Advisory Basis, of the Compensation of the Company’s Named Executive Officers. 3. Approval, on an Advisory Basis, of the Frequency of Future Stockholder Advisory Votes to Approve the Compensation of the Company’s Named Executive Officers. 4. Ratification of PricewaterhouseCoopers LLP as the Company’s Independent Registered Public Accounting Firm for the year ending December 31, 2026. PLEASE NOTE – YOU CANNOT VOTE BY RETURNING THIS NOTICE. You may vote your shares online or by phone or you may request a paper copy of the proxy materials to receive a proxy card. Here’s how to order a copy of the proxy materials and select delivery preferences: Current and future delivery requests can be submitted using the options below. If you request an email copy, you will receive an email with a link to the current meeting materials. PLEASE NOTE: You must use the number in the shaded bar on the reverse side when requesting a copy of the proxy materials. — Internet – Go to www.investorvote.com/curb. — Phone – Call us free of charge at 1-866-641-4276. — Email – Send an email to [email protected] with “Proxy Materials Curbline Properties Corp.” in the subject line. Include your full name and address, plus the number located in the shaded bar on the reverse side, and state that you want a paper copy of the meeting materials. To facilitate timely delivery, requests for a paper copy of proxy materials must be received by April 27, 2026.