The latest version of FFx40 Software is 5.1.6. This was released in Septemeber of 2018. 
The process for updating your FFx40 is initiated from the unit itself. The unit will 
download updates from our update server (or a user defined update server) when instructed. 
This is in contrast to how updates are performed with the FFx30 model FaxFinders. 
As the system administrator, you do not upload firmware upgrade files to the FFx40. 
To view a list of software changes and to update the software of your FFx40 fax server, 
log into the WEB Administration menu of your unit and navigate to System Configuration > 
Software Update menu. The "Update Source" is the URL your FFx40 will navigate to, 
when checking for software updates.  Clicking on the "Check for Updates" button will 
cause the FFx40 FaxFinder to check the designated site for a newer version of software. 
If an update is available it will be listed as such along with an Upgrade button and a 
README document about the new version. The software update is downloaded from the Update 
Source when the Update button is clicked. If the update is downloaded successfully the 
unit will apply the update and reboot the unit. 

Important: Do not power off the FFx40 during the update process.

Version 5.1.6:

Changes since version 5.0.5.8

Features:
- Added support for PDF 1.5 cover pages
- Added support for .jpg, .doc and .bmp files
- Added footer option

Bug Fixes:
- Updated SSL/SSH
   SSL - 1.0.2m
   SSH - 7.6p1
- Fixed OpenSSH Vulnerablities
   CVE-2016-10012
   CVE-2015-8325
- Fixed issue with preprocessing error when converting files to fax
- Fixed issue with X-FRAME_OPTIONS in HTTP header
- Fixed issue with root certificates
- Fixed issue with AD phone number with a preceding + 
- Fixed issue where FaxFinder segfaults with " in Full Name 
   Note: Analog models this will result in a failed fax.  
- Fixed issue with Rejected PDFs with application/octet-stream MIME
- Fixed issue with Email Notifications and shares with spaces
- Fixed issue with UNC path limited to 50 characters, it is now 256 characters.
- Fixed issue where UNC path in email was unclickable
- Fixed security bug related to injecting SQL through call details request
- Fixes issue with SFTP not showing directories which made using multiple directories hard
- Fixed issue with duplicate emails and Inbound Fax Entries
- Fixed issue with Inbound Status showing incorrect recipients
- Fixes for duplicate faxes with one etherFAX account and multiple FaxFinders
- Fixed issue where you could create a new user with a blank password
- Fixed issue where T.37 settings are ignored when the username is "unknown"
- Removed TLS1.0 support
- Updated SIP/T.38 Stack

Version 5.0.5.8:

Changes since version 5.0.5.5

Bug Fixes:
- Fixed issue with analog (FFx40s) FaxFinders not showing Hardware ID on the System Configuration -> Software Update page

Version 5.0.5.5:

Changes since version 5.0.5.1

Bug Fixes:
- Remove all non-numeric characters from the Caller ID Number when using SIP/T.38
- Fixed issue where some files were world writable when a fax is received
- Fixed some issues with the help files
- Fixed issue with long uploads to etherFAX causes the fax to be sent several times

Version 5.0.5.1:

Changes since version 5.0.5

Bug Fixes:
- Fixed issue with duplicate emails and Inbound Fax Entries
- Fixed issue with Inbound Status showing incorrect receipients

Version 5.0.5

Changes since version 4.1.2:

Features:
- Added support for hybrid mode allowing for fax over IP
- Added wildcard support for extensions in the Inbound Routing

Bug Fixes:
- Fixed Internal Server Error from inbound_status API call if there is an inbound fax
- Added hover help when adding an inbound route to help avoid mis-configuration

Version 4.1.2

Changes since version 4.0.0:

Bug Fixes
- Addressed numerous security issues
- Don't reject pdf attachments that come in as application/octet stream
- Fixed issue with AD turning "-" to " "
- Added caller name/number to call_log and inbound_log API calls
- Increased the number of simultaneous connections to 150. It was 50


Changes since version 3.5.2:

Features
- Added option to set the fax page size for the inbound and outbound faxes

Bug Fixes
- Added caller ID info to the call log and call log details web pages
- Fixes issue with the inability to disable "Allow simultaneous faxing to same number"
- Added support for AD attributes without a "-"
- RC4 ciphers are no longer supported


Changes since version 3.4.3:

Bug Fixes
- Fixes an issue with the counter (%X) used to customize filenames
- Added more logging when making space when the drive is full
- Fixes the issue connecting to Active Directory
- Modem logs are now written in local time vs UTC
- Added ffldaplib to the list of files that are rotated
- Changed how many completed outbound faxes are removed when the threshold is reached


Changes since version 3.3.8:

Bug Fixes
- Fixes a bug trying to deliver a partial fax
- By passed import error
- Added hplip supported
- Increased the max length of the printer uri, shares unc, and sftp server from 50 to 256
- Fixes the GHOST vulnerability