The GUP generic update process in Notepad++ before 4.8.1 does not properly verify the authenticity of updates, which allows man-in-the-middle attackers to execute arbitrary code via a Trojan horse update, as demonstrated by evilgrade and DNS cache poisoning.
Stack-based buffer overflow in LexRuby.cxx (SciLexer.dll) in Scintilla 1.73, as used by notepad++ 4.1.1 and earlier, allows user-assisted remote attackers to execute arbitrary code via certain Ruby (.rb) files with long lines. NOTE: this was originally reported as a vulnerability in notepad++.