diff --git a/lib/octocatalog-diff/catalog-diff/display/text.rb b/lib/octocatalog-diff/catalog-diff/display/text.rb
index 923f665b..d38d8ac3 100644
--- a/lib/octocatalog-diff/catalog-diff/display/text.rb
+++ b/lib/octocatalog-diff/catalog-diff/display/text.rb
@@ -307,6 +307,9 @@ def self.adjust_position_of_plus_minus(string_in)
         # @param string_in [String] Input string, which might contain trailing whitespace
         # @return [String] Modified string
         def self.make_trailing_whitespace_visible(string_in)
+          if string_in.length > 1000
+            raise ArgumentError, "Input string too long"
+          end
           return string_in unless string_in =~ /\A((?:.|\n)*?)(\s+)(\e\[0m)?\Z/
           beginning = Regexp.last_match(1)
           trailing_space = Regexp.last_match(2)
diff --git a/lib/octocatalog-diff/catalog-util/builddir.rb b/lib/octocatalog-diff/catalog-util/builddir.rb
index 515c42b3..a0e8f83a 100644
--- a/lib/octocatalog-diff/catalog-util/builddir.rb
+++ b/lib/octocatalog-diff/catalog-util/builddir.rb
@@ -155,6 +155,9 @@ def install_fact_file(logger, options)
         elsif options[:fact_file]
           raise Errno::ENOENT, "Fact file #{options[:fact_file]} does not exist" unless File.file?(options[:fact_file])
           fact_file_opts = { fact_file_string: File.read(options[:fact_file]) }
+          if options[:fact_file].length > 1000
+            raise ArgumentError, "Input too long"
+          end
           fact_file_opts[:backend] = Regexp.last_match(1).to_sym if options[:fact_file] =~ /.*\.(\w+)$/
           OctocatalogDiff::Facts.new(fact_file_opts)
         else
diff --git a/rake/doc.rb b/rake/doc.rb
index d73eadef..bfdcb193 100644
--- a/rake/doc.rb
+++ b/rake/doc.rb
@@ -21,7 +21,7 @@ def file_content(filename)
       @fc ||= {}
       @fc[filename] ||= begin
         comments = []
-        IO.readlines(filename).each do |line|
+        File.readlines(filename).each do |line|
           next if line =~ /^#\s*@/
           next if line.strip == '# frozen_string_literal: true'
           if line =~ /^#(.+)/