New mozilla-firefox packages are available for Slackware 14.2 and -current to fix security issues.

Here are the details from the Slackware 14.2 ChangeLog:
+--------------------------+
patches/packages/mozilla-firefox-60.7.0esr-i686-1_slack14.2.txz: Upgraded.
This release contains security fixes and improvements. Some of the patched
flaws are considered critical, and could be used to run attacker code and
install software, requiring no user interaction beyond normal browsing.
For more information, see:
https://www.mozilla.org/security/known-vulnerabilities/firefoxESR.html
https://www.mozilla.org/en-US/security/advisories/mfsa2019-14/
https://www.mozilla.org/en-US/security/advisories/mfsa2019-14/#CVE-2019-9815
https://www.mozilla.org/en-US/security/advisories/mfsa2019-14/#CVE-2019-9816
https://www.mozilla.org/en-US/security/advisories/mfsa2019-14/#CVE-2019-9817
https://www.mozilla.org/en-US/security/advisories/mfsa2019-14/#CVE-2019-9818
https://www.mozilla.org/en-US/security/advisories/mfsa2019-14/#CVE-2019-9819
https://www.mozilla.org/en-US/security/advisories/mfsa2019-14/#CVE-2019-9820
https://www.mozilla.org/en-US/security/advisories/mfsa2019-14/#CVE-2019-11691
https://www.mozilla.org/en-US/security/advisories/mfsa2019-14/#CVE-2019-11692
https://www.mozilla.org/en-US/security/advisories/mfsa2019-14/#CVE-2019-11693
https://www.mozilla.org/en-US/security/advisories/mfsa2019-14/#CVE-2019-7317
https://www.mozilla.org/en-US/security/advisories/mfsa2019-14/#CVE-2019-9797
https://www.mozilla.org/en-US/security/advisories/mfsa2019-14/#CVE-2018-18511
https://www.mozilla.org/en-US/security/advisories/mfsa2019-14/#CVE-2019-11694
https://www.mozilla.org/en-US/security/advisories/mfsa2019-14/#CVE-2019-11698
https://www.mozilla.org/en-US/security/advisories/mfsa2019-14/#CVE-2019-5798
https://www.mozilla.org/en-US/security/advisories/mfsa2019-14/#CVE-2019-9800
(* Security fix *)
+--------------------------+


Where to find the new packages:
+-----------------------------+

Thanks to the friendly folks at the OSU Open Source Lab
(http://osuosl.org) for donating FTP and rsync hosting
to the Slackware project!

Also see the "Get Slack" section on http://slackware.com for
additional mirror sites near you.

Updated package for Slackware 14.2:
ftp://ftp.slackware.com/pub/slackware/slackware-14.2/patches/packages/mozilla-firefox-60.7.0esr-i686-1_slack14.2.txz

Updated package for Slackware x86_64 14.2:
ftp://ftp.slackware.com/pub/slackware/slackware64-14.2/patches/packages/mozilla-firefox-60.7.0esr-x86_64-1_slack14.2.txz

Updated package for Slackware -current:
ftp://ftp.slackware.com/pub/slackware/slackware-current/slackware/xap/mozilla-firefox-60.7.0esr-i686-1.txz

Updated package for Slackware x86_64 -current:
ftp://ftp.slackware.com/pub/slackware/slackware64-current/slackware64/xap/mozilla-firefox-60.7.0esr-x86_64-1.txz


MD5 signatures:
+-------------+

Slackware 14.2 package:
9bb86b28639fe241a285ae8868f6fd3c mozilla-firefox-60.7.0esr-i686-1_slack14.2.txz

Slackware x86_64 14.2 package:
71cfd983350a89459015e89af1f4cf46 mozilla-firefox-60.7.0esr-x86_64-1_slack14.2.txz

Slackware -current package:
02f5b3d10ba9ef7a094f862b1a9b4120 xap/mozilla-firefox-60.7.0esr-i686-1.txz

Slackware x86_64 -current package:
b4ccd8857ce8355105c0595cf2d84154 xap/mozilla-firefox-60.7.0esr-x86_64-1.txz


Installation instructions:
+------------------------+

Upgrade the package as root:
# upgradepkg mozilla-firefox-60.7.0esr-i686-1_slack14.2.txz

  Firefox (SSA:2019-141-01) Update for Slackware