Exhibit 24 [CoStar Group Logo] LIMITED POWER OF ATTORNEY FOR SECTION 16 REPORTING OBLIGATIONS Know all by these presents, that the undersigned hereby makes, cons�tutes and appoints each of Gene Boxer and Michael Rosenthall, each ac�ng individually, as the undersigned's true and lawful atorney-in- fact, with full power and authority as hereina�er described on behalf of and in the name, place and stead of the undersigned to: (1) prepare, execute, acknowledge, deliver and file Forms 3, 4, and 5 (including any amendments thereto) with respect to the securi�es of CoStar Group, Inc., a Delaware corpora�on (the "Company"), with the United States Securi�es and Exchange Commission, any na�onal securi�es exchanges and the Company, in accordance with Sec�on 16(a) of the Securi�es Exchange Act of 1934 and the rules and regula�ons promulgated thereunder, as amended from �me to �me (the "Exchange Act"); (2) seek or obtain, as the undersigned's representa�ve and on the undersigned's behalf, informa�on on transac�ons in the Company's securi�es from any third party, including brokers, employee benefit plan administrators and trustees, and the undersigned hereby authorizes any such person to release any such informa�on to the undersigned and approves and ra�fies any such release of informa�on; and (3) perform any and all other acts which in the discre�on of such atorney-in-fact are necessary or desirable for and on behalf of the undersigned in connec�on with the foregoing. The undersigned acknowledges that: (1) this Power of Atorney authorizes, but does not require, each such atorney-in-fact to act in their discre�on on informa�on provided to such atorney-in-fact without independent verifica�on of such informa�on; (2) any documents prepared and/or executed by either such atorney-in-fact on behalf of the undersigned pursuant to this Power of Atorney will be in such form and will contain such informa�on and disclosure as such atorney-in-fact, in his or her discre�on, deems necessary or desirable; (3) neither the Company nor either of such atorneys-in-fact assumes (i) any liability for the undersigned's responsibility to comply with the requirements of the Exchange Act, (ii) any liability of the undersigned for any failure to comply with such requirements, or (iii) any obliga�on or liability of the undersigned for profit disgorgement under Sec�on 16(b) of the Exchange Act; and (4) this Power of Atorney does not relieve the undersigned from responsibility for compliance with the undersigned's obliga�ons under the Exchange Act, including without limita�on the repor�ng requirements under Sec�on 16 of the Exchange Act. The undersigned hereby gives and grants each of the foregoing atorneys-in-fact full power and authority to do and perform all and every act and thing whatsoever requisite, necessary or appropriate to be done in and about the foregoing maters as fully to all intents and purposes as the undersigned might or could

do if present, hereby ra�fying all that each such atorney-in-fact of, for and on behalf of the undersigned, shall lawfully do or cause to be done by virtue of this Limited Power of Atorney. This Power of Atorney shall remain in full force and effect un�l revoked by the undersigned in a signed wri�ng delivered to each such atorney-in-fact. IN WITNESS WHEREOF, the undersigned has caused this Power of Atorney to be executed as of this 24th day of July, 2023. /s/ Angelique Brunner Angelique Brunner On this 24th day of July, 2023, Angelique Brunner personally appeared before me, and acknowledged that she executed the foregoing instrument for the purposes therein contained. IN WITNESS WHEREOF, I have hereunto set my hand and official seal. /s/ Tanya Blalock Notary Public District of Columbia My Commission Expires December 14, 2027