Please disclose any vulnerabilities found responsibly - report any security problems found to the maintainers privately.
+PHPMailer versions prior to 5.2.22 (released January 2017) have a local file disclosure vulnerability if content passed into `msgHTML()` is sourced from unfiltered user input. Also note that `addAttachment` (just like `file_get_contents`, `passthru`, `unlink`, etc) should not be passed user-sourced params either!
PHPMailer versions prior to 5.2.20 (released December 28th 2016) are vulnerable to [CVE-2016-10045](https://web.nvd.nist.gov/view/vuln/detail?vulnId=CVE-2016-10045) a remote code execution vulnerability, responsibly reported by [Dawid Golunski](https://legalhackers.com/advisories/PHPMailer-Exploit-Remote-Code-Exec-CVE-2016-10045-Vuln-Patch-Bypass.html), and patched by Paul Buonopane (@Zenexer).
PHPMailer versions prior to 5.2.18 (released December 2016) are vulnerable to [CVE-2016-10033](https://web.nvd.nist.gov/view/vuln/detail?vulnId=CVE-2016-10033) a remote code execution vulnerability, responsibly reported by [Dawid Golunski](http://legalhackers.com/advisories/PHPMailer-Exploit-Remote-Code-Exec-CVE-2016-10033-Vuln.html).