Sec Form 4/A Filing - CONSTELLATION SOFTWARE INC @ Sabre Corp - 2026-02-27

FORM 4/A Check this box if no longer subject to Section 16. Form 4 or Form 5 obligations may continue. See Instruction 1(b).

UNITED STATES SECURITIES AND EXCHANGE COMMISSION Washington, D.C. 20549 STATEMENT OF CHANGES IN BENEFICIAL OWNERSHIP Filed pursuant to Section 16(a) of the Securities Exchange Act of 1934, Section 17(a) of the Public Utility Holding Company Act of 1935 or Section 30(h) of the Investment Company Act of 1940

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1. Name and Address of Reporting Person CONSTELLATION SOFTWARE INC 2. Issuer Name and Ticker or Trading Symbol Sabre Corp [ SABR] 5. Relationship of Reporting Person(s) to Issuer (Check all applicable) _____ Director X __ 10% Owner _____ Officer (give title below) _____ Other (specify below) (Last) (First) (Middle) 66 WELLINGTON STREET WEST, SUITE 5300, TD BANK TOWER 3. Date of Earliest Transaction (MM/DD/YY) 02/27/2026 (Street) TORONTOM5K 1E6 4. If Amendment, Date Original Filed (MM/DD/YY) 03/03/2026 6. Individual or Joint/Group Filing (Check Applicable Line) _____ Form filed by One Reporting Person __ X __ Form filed by More than One Reporting Person (City) (State) (Zip)

Table I - Non-Derivative Securities Acquired, Disposed of, or Beneficially Owned 1.Title of Security (Instr. 3) 2. Transaction Date (MM/DD/YY) 2A. Deemed Execution Date, if any (MM/DD/YY) 3. Transaction Code (Instr. 8) 4. Securities Acquired (A) or Disposed of (D) (Instr. 3, 4 and 5) 5. Amount of Securities Beneficially Owned Following Reported Transaction(s) (Instr. 3 and 4) 6. Ownership Form: Direct (D) or Indirect (I) (Instr. 4) 7. Nature of Indirect Beneficial Ownership (Instr. 4) Code V Amount (A) or (D) Price Common Stock, $0.01 par value ( 1 ) 02/27/2026 P 10,634,702 A $ 1.1605 ( 3 ) 50,157,523 D ( 2 )

Table II - Derivative Securities Acquired, Disposed of, or Beneficially Owned ( e.g. , puts, calls, warrants, options, convertible securities) 1. Title of Derivative Security (Instr. 3) 2. Conversion or Exercise Price of Derivative Security 3. Transaction Date (MM/DD/YY) 3A. Deemed Execution Date, if any (MM/DD/YY) 4. Transaction Code (Instr. 8) 5. Number of Derivative Securities Acquired (A) or Disposed of (D) (Instr. 3, 4, and 5) 6. Date Exercisable and Expiration Date (MM/DD/YY) 7. Title and Amount of Underlying Securities (Instr. 3 and 4) 8. Price of Derivative Security (Instr. 5) 9. Number of Derivative Securities Beneficially Owned Following Reported Transaction(s) (Instr. 4) 10. Ownership Form of Derivative Security: Direct (D) or Indirect (I) (Instr. 4) 11. Nature of Indirect Beneficial Ownership (Instr. 4) Code V (A) (D) Date Exercisable Expiration Date Title Amount or Number of Shares

Reporting Owners Reporting Owner Name / Address Relationships Director 10% Owner Officer Other CONSTELLATION SOFTWARE INC 66 WELLINGTON STREET WEST, SUITE 5300 TD BANK TOWER TORONTOM5K 1E6 X Constellation Canadian Holdings Inc. 66 WELLINGTON STREET WEST, SUITE 5300 TD BANK TOWER TORONTOM5K 1E6 X Miller Mark Robert 66 WELLINGTON STREET WEST, SUITE 5300 TD BANK TOWER TORONTOM5K 1E6 X Signatures /s/ Constellation Software Inc., By Mark Dennison, Secretary and General Counsel 03/30/2026 Signature of Reporting Person Date /s/ Constellation Canadian Holdings Inc., By Jamal Baksh, Chief Financial Officer 03/30/2026 Signature of Reporting Person Date /s/ Mark Miller 03/30/2026 Signature of Reporting Person Date

Explanation of Responses:

( 1 )This Form 4 is filed jointly by Constellation Software Inc ("Constellation Software"), Constellation Canadian Holdings Inc. ("Constellation Holdings"), and Mark Miller (collectively, the "Reporting Persons"). The EDGAR filing codes for Constellation Holdings and Mark Miller were not available at the time of this required filing, and the Reporting Persons intend to amend this Form 3 to include such Reporting Persons in the filing when such codes are available. Each Reporting Person disclaims beneficial ownership of the securities of the Issuer reported herein except to the extent of his or its pecuniary interest therein, and this report shall not be deemed to be an admission that any Reporting Person is the beneficial owner of such securities for purposes of Section 16 or for any other purpose. ( 2 )Securities owned directly by Constellation Holdings. As the direct parent company of Constellation Holdings, Constellation Software may be deemed to beneficially own the securities owned directly by Constellation Holdings. Mr. Miller, as the President of Constellation Software, may be deemed to beneficially own the securities owned directly by Constellation Holdings. ( 3 )The reported price represents a weighted average price. These shares were purchased in multiple transactions at prices ranging from $1.07 to $1.24 per share. The Reporting Persons undertake to provide to the Issuer, any security holder of the Issuer or the staff of the Securities and Exchange Commission, upon request, full information regarding the number of shares purchased at each separate price within the range set forth in this footnote.

Remarks: This Form 4 is being amended to add each of Constellation Canadian Holdings Inc. and Mr. Miller as a reporting person upon receipt of their EDGAR codes.

Reminder: Report on a separate line for each class of securities beneficially owned directly or indirectly.

* If the form is filed by more than one reporting person, see Instruction 4(b)(v).

** Intentional misstatements or omissions of facts constitute Federal Criminal Violations. See 18 U.S.C. 1001 and 15 U.S.C. 78ff(a).

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