<?xml version="1.0"?>
<ownershipDocument>

    <schemaVersion>X0206</schemaVersion>

    <documentType>3/A</documentType>

    <periodOfReport>2026-03-13</periodOfReport>

    <dateOfOriginalSubmission>2026-03-13</dateOfOriginalSubmission>

    <noSecuritiesOwned>0</noSecuritiesOwned>

    <issuer>
        <issuerCik>0001076378</issuerCik>
        <issuerName>CEMEX SAB DE CV</issuerName>
        <issuerTradingSymbol>CX</issuerTradingSymbol>
    </issuer>

    <reportingOwner>
        <reportingOwnerId>
            <rptOwnerCik>0001427501</rptOwnerCik>
            <rptOwnerName>Fernandez-Carbajal Francisco Javier</rptOwnerName>
        </reportingOwnerId>
        <reportingOwnerAddress>
            <rptOwnerStreet1>P.O. BOX 8999</rptOwnerStreet1>
            <rptOwnerStreet2>C/O VISA INC.</rptOwnerStreet2>
            <rptOwnerCity>SAN FRANCISCO</rptOwnerCity>
            <rptOwnerState>CA</rptOwnerState>
            <rptOwnerZipCode>94128-8999</rptOwnerZipCode>
            <rptOwnerStateDescription></rptOwnerStateDescription>
        </reportingOwnerAddress>
        <reportingOwnerRelationship>
            <isDirector>1</isDirector>
            <isOfficer>0</isOfficer>
            <isTenPercentOwner>0</isTenPercentOwner>
            <isOther>0</isOther>
        </reportingOwnerRelationship>
    </reportingOwner>

    <nonDerivativeTable>
        <nonDerivativeHolding>
            <securityTitle>
                <value>Ordinary Participation Certificates (CEMEX.CPO) BMV MEXICO</value>
            </securityTitle>
            <postTransactionAmounts>
                <sharesOwnedFollowingTransaction>
                    <value>1272769</value>
                </sharesOwnedFollowingTransaction>
            </postTransactionAmounts>
            <ownershipNature>
                <directOrIndirectOwnership>
                    <value>D</value>
                </directOrIndirectOwnership>
            </ownershipNature>
        </nonDerivativeHolding>
    </nonDerivativeTable>

    <remarks>1,272,769 securities were incorrectly listed as American Depositary Shares with the ticker symbol CX.

The correct ownership should be 1,272,769 Ordinary Participation Certificates (CEMEX.CPO) BMV MEXICO.</remarks>

    <ownerSignature>
        <signatureName>Javier Francisco Fernandez Carbajal</signatureName>
        <signatureDate>2026-03-13</signatureDate>
    </ownerSignature>
</ownershipDocument>
