v3.26.1
Document and Entity Information
Jun. 26, 2026
Document and Entity Information [Abstract]  
Document Type 8-K
Document Period End Date Jun. 26, 2026
Entity Registrant Name Catalyst Bancorp, Inc.
Entity Incorporation, State or Country Code LA
Entity File Number 001-40893
Entity Tax Identification Number 86-2411762
Entity Address, Address Line One 235 N. Court Street
Entity Address, City or Town Opelousas
Entity Address State Or Province LA
Entity Address, Postal Zip Code 70570
City Area Code 337
Local Phone Number 948-3033
Written Communications false
Soliciting Material false
Pre-commencement Tender Offer false
Pre-commencement Issuer Tender Offer false
Title of 12(b) Security Common Stock
Trading Symbol CLST
Security Exchange Name NASDAQ
Entity Emerging Growth Company true
Entity Ex Transition Period false
Entity Central Index Key 0001849867
Amendment Flag false