The customer will be able to download the Hotfix from the TIBCO Support Customer Portal Web UI using their username and password for the TIBCO Support Web page. Once logged on they can find the Hotfix under the Download Menu :

AvailableDownloads/BusinessConnect/RosettaNet/5.3.0/hotfix-01

For instructions on how can TIBCO customers download / access all GA hotfixes , Refer to Article 000022290 :  https://support.tibco.com/s/article/hotfix.

Listed below is a summary of updates included. Refer to the associated readme document for any additional information.================================================================================
Closed Issues in 5.3.0_HF-001 (This Release)

BCRN-1190
When TIBCO BusinessConnect send out HTTP message with header content-type, if
the content-type include micalg parameter and the value of micalg parameter is
secure hash algorithm (like sha-1 and sha-256), secure hash algorithm name should
not include dash char(like sha1 and sha256).
Note: This fix requires TIBCO BusinessConnect 7.2.0 Hotfix 1 or 
TIBCO BusinessConnect 7.2.1 Hotfix 1 to be installed.

NOTE:  In order for this fix to be implemented, the following property has to be added to the deployed BC engine TRA file:

java.property.bc.outbound.remove.dash.from.micalg=true

BCRN-1191
The request body is missing carriage return character at the end of each line
for S/MIME.