Adobe also has critical Reader and Flash updates this month & users should promptly get up-to-date (esp. as prompted by automated update notices)

Adobe December 2018 Security Update Fixes Reader, Acrobat

Adobe has patched 87 vulnerabilities for Acrobat and Reader in its December Patch Tuesday update, including a slew of critical flaws that would allow arbitrary code-execution.  The scheduled update comes less than a week after Adobe released several out-of-band fixes for Flash Player, including a critical vulnerability (CVE-2018-15982) that it said is being exploited in the wild. That’s a use-after-free flaw enabling arbitrary code-execution in Flash.