parses update versions, some managed by `sudo softwareupdate --background-critical`, ported from an applescript found at https://www.jamf.com/jamf-nation/discussions/19111/xprotect-status-extension-attribute

report_critical_update_versions.py

#!/usr/bin/python

# Copyright (c) 2019 University of Utah Student Computing Labs. ################
# All Rights Reserved.
#
# Permission to use, copy, modify, and distribute this software and
# its documentation for any purpose and without fee is hereby granted,
# provided that the above copyright notice appears in all copies and
# that both that copyright notice and this permission notice appear
# in supporting documentation, and that the name of The University
# of Utah not be used in advertising or publicity pertaining to
# distribution of the software without specific, written prior
# permission. This software is supplied as is without expressed or
# implied warranties of any kind.
################################################################################

# report_critical_update_versions.py ###########################################
# 07/12/19, v0.4, todd.mcdaniel@utah.edu
#
# works with Python 2 or 3
#
# more of a learning experience than a useful product.
# ported from an applescript found here:
# https://www.jamf.com/jamf-nation/discussions/19111/xprotect-status-extension-attribute
# parses update versions, some managed by `sudo softwareupdate --background-critical`
#
################################################################################

from __future__ import print_function

import datetime
import os
import subprocess
import sys


def main():

    # format for update description:
    # update title, file for date calculation, file for version discovery, version command to use

    py2 = False
    py3 = False

    if sys.version_info[0] == 2:
        py2 = True
    elif sys.version_info[0] == 3:
        py3 = True

    updates = [
        ["XProtect", "/System/Library/CoreServices/XProtect.bundle/Contents/Resources/XProtect.meta.plist", "/System/Library/CoreServices/XProtect.bundle/Contents/Resources/XProtect.meta.plist", "Version"],
        ["Gatekeeper", "/private/var/db/gkopaque.bundle/Contents/version.plist", "/private/var/db/gkopaque.bundle/Contents/version.plist", "CFBundleShortVersionString"],
        ["SIP", "/System/Library/Sandbox/Compatibility.bundle/Contents/version.plist", "/System/Library/Sandbox/Compatibility.bundle/Contents/version.plist", "CFBundleShortVersionString"],
        ["MRT", "/System/Library/CoreServices/MRT.app/Contents/version.plist", "/System/Library/CoreServices/MRT.app/Contents/version", "CFBundleShortVersionString"],
        ["Core Suggestions", "/System/Library/Intelligent Suggestions/Assets.suggestionsassets/Contents/version.plist", "/System/Library/Intelligent Suggestions/Assets.suggestionsassets/Contents/version.plist", "CFBundleShortVersionString"],
        ["Incompatible Kernel Ext.", "/System/Library/Extensions/AppleKextExcludeList.kext/Contents/version.plist", "/System/Library/Extensions/AppleKextExcludeList.kext/Contents/version", "CFBundleShortVersionString"],
        ["Chinese Word List", "/usr/share/mecabra/updates/com.apple.inputmethod.SCIM.bundle/Contents/version.plist", "/usr/share/mecabra/updates/com.apple.inputmethod.SCIM.bundle/Contents/info", "SUVersionString"],
        ["Core LSKD (dkrl)", "/usr/share/kdrl.bundle/info.plist", "/usr/share/kdrl.bundle/info", "CFBundleVersion"]
    ]

    print("-" * 50)
    print("| {:<24} | {}      | {:>6}|".format("Name", "Dated", "Version"))

    for _, data in enumerate(updates):

        print("|" + "-" * 26 + "+" + "-" * 12 + "+" + "-" * 8 + "|")

        version_number = ""
        try:
            mod_time = datetime.datetime.fromtimestamp(os.path.getmtime(data[1]))
            formatted_modtime = mod_time.strftime('%Y.%m.%d')

            try:
                version_string = subprocess.check_output(["defaults", "read", data[2], data[3]])
                if py2:
                    version_number = version_string.strip()
                if py3:
                    version_number = str(version_string.strip(), 'utf-8')
            except Exception as this_exception:
                print(this_exception)

            print("| {:<24} | {} | {:>6} |".format(data[0], formatted_modtime, version_number))

        except OSError:
            formatted_modtime = "Deprecated/missing."
            print("| {:<24} | {} |".format(data[0], formatted_modtime))

    print("-" * 50)


if __name__ == '__main__':
    main()

Sample output:

Name                     Date      Version
__________________________________________
XProtect                 2017.01.17   2087
Gatekeeper               2016.12.15    107
SIP                      2015.10.23   12.0
MRT                      2017.01.17   1.14
Core Suggestions         2017.01.03    778
Incompatible Kernel Ext. 2016.11.29 11.6.1
Chinese Word List        2016.08.24   4.22
Core LSKD (dkrl)         2014.06.24      8

Thank you Todd! Here's a Swift version written by me.

Sample output of new release:

--------------------------------------------------
| Name                     | Dated      | Version|
|--------------------------+------------+--------|
| XProtect                 | 2019.04.26 |   2103 |
|--------------------------+------------+--------|
| Gatekeeper               | 2019.07.12 |    172 |
|--------------------------+------------+--------|
| SIP                      | 2019.02.22 |   15.0 |
|--------------------------+------------+--------|
| MRT                      | 2019.07.15 |   1.46 |
|--------------------------+------------+--------|
| Core Suggestions         | Deprecated/missing. |
|--------------------------+------------+--------|
| Incompatible Kernel Ext. | 2019.04.10 | 14.5.1 |
|--------------------------+------------+--------|
| Chinese Word List        | Deprecated/missing. |
|--------------------------+------------+--------|
| Core LSKD (dkrl)         | 2019.02.28 |      8 |
--------------------------------------------------