Company: CIB
Filing Date: 2025-05-16
Form Type: 6-K
Source: 0001193125-25-121769
Chunk: 0

Company: Grupo Cibest S.A.
Filing Date: 2025-05-16
Form: 6-K
Chunk 0
---
### UNITED STATES

### SECURITIES
AND EXCHANGE COMMISSION

Washington, D.C. 20549

FORM 6-K

REPORT OF FOREIGN PRIVATE ISSUER

PURSUANT TO RULE 13a-16OR 15d-16

OF THE SECURITIES EXCHANGE ACT OF 1934

For the month of May, 2025

Commission File Number 001-42656

Grupo Cibest S.A.

(Translation of registrant’s name into English)

Cra. 48 

# 26-85
Medellín, Colombia

(Address of principal executive offices)

Indicate by check mark whether the registrant files or will file annual reports under cover of Form 20-F or Form 40-F.

Form 20-F ☑ Form 40-F ☐

SIGNATURE 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, thereunto duly authorized.

|                   |     | GRUPO CIBEST S.A. 
 (Registrant)      |     |                                        |
| Date May 16. 2025 |     | By:               |     | /s/ MAURICIO BOTERO WOLFF.             |
|                   |     | Name:             |     | Mauricio Botero Wolff                  |
|                   |     | Title:            |     | Vice President of Strategy and Finance |

2

May 16, 2025 Medellín, Colombia EXTRAORDINARY GENERAL SHAREHOLDERS’ MEETING NOTICE The President of Grupo Cibest S.A. (“Grupo Cibest”) hereby calls the shareholders holding common shares to an Extraordinary General Shareholders’ Meeting, which will take place, in person, on June 9, 2025, at 10:00 am, at the offices of the management of Grupo Cibest, located at Carrera 48 Número 26-85,Torre Sur, Piso 11, in the city of Medellín. The proposed agenda for the meeting is as follows:

| 1. | Verification of quorum |

| 2. | Reading of the agenda |

| 3. | Election of commission for vote count, approval, and execution of the minutes |

| 4. | Election of the Board of Directors for the period June 2025 – March 2027 |

| 5. | Remuneration of the Board