diff --git lib/rubygems.rb lib/rubygems.rb
index 0685bcb3c6..a5a9202e56 100644
--- lib/rubygems.rb
+++ lib/rubygems.rb
@@ -10,7 +10,7 @@
 require 'thread'
 
 module Gem
-  VERSION = "2.6.14"
+  VERSION = "2.6.14.1"
 end
 
 # Must be first since it unloads the prelude from 1.9.2
diff --git lib/rubygems/commands/owner_command.rb lib/rubygems/commands/owner_command.rb
index 4b99434e87..2ee7f84462 100644
--- lib/rubygems/commands/owner_command.rb
+++ lib/rubygems/commands/owner_command.rb
@@ -62,7 +62,7 @@ def show_owners name
     end
 
     with_response response do |resp|
-      owners = YAML.load resp.body
+      owners = Gem::SafeYAML.load resp.body
 
       say "Owners for gem: #{name}"
       owners.each do |owner|
diff --git lib/rubygems/package.rb lib/rubygems/package.rb
index 77811ed5ec..b5a5fe2a26 100644
--- lib/rubygems/package.rb
+++ lib/rubygems/package.rb
@@ -378,7 +378,7 @@ def extract_tar_gz io, destination_dir, pattern = "*" # :nodoc:
             File.dirname destination
           end
 
-        FileUtils.mkdir_p mkdir, mkdir_options
+        mkdir_p_safe mkdir, mkdir_options, destination_dir, entry.full_name
 
         open destination, 'wb' do |out|
           out.write entry.read
@@ -416,20 +416,35 @@ def install_location filename, destination_dir # :nodoc:
     raise Gem::Package::PathError.new(filename, destination_dir) if
       filename.start_with? '/'
 
-    destination_dir = File.realpath destination_dir if
-      File.respond_to? :realpath
+    destination_dir = realpath destination_dir
     destination_dir = File.expand_path destination_dir
 
     destination = File.join destination_dir, filename
     destination = File.expand_path destination
 
     raise Gem::Package::PathError.new(destination, destination_dir) unless
-      destination.start_with? destination_dir
+      destination.start_with? destination_dir + '/'
 
     destination.untaint
     destination
   end
 
+  def mkdir_p_safe mkdir, mkdir_options, destination_dir, file_name
+    destination_dir = realpath File.expand_path(destination_dir)
+    parts = mkdir.split(File::SEPARATOR)
+    parts.reduce do |path, basename|
+      path = realpath path  unless path == ""
+      path = File.expand_path(path + File::SEPARATOR + basename)
+      lstat = File.lstat path rescue nil
+      if !lstat || !lstat.directory?
+        unless path.start_with? destination_dir and (FileUtils.mkdir path, mkdir_options rescue false)
+          raise Gem::Package::PathError.new(file_name, destination_dir)
+        end
+      end
+      path
+    end
+  end
+
   ##
   # Loads a Gem::Specification from the TarEntry +entry+
 
@@ -603,6 +618,10 @@ def verify_files gem
       raise Gem::Package::FormatError.new \
               'package content (data.tar.gz) is missing', @gem
     end
+
+    if duplicates = @files.group_by {|f| f }.select {|k,v| v.size > 1 }.map(&:first) and duplicates.any?
+      raise Gem::Security::Exception, "duplicate files in the package: (#{duplicates.map(&:inspect).join(', ')})"
+    end
   end
 
   ##
@@ -616,6 +635,16 @@ def verify_gz entry # :nodoc:
     raise Gem::Package::FormatError.new(e.message, entry.full_name)
   end
 
+  if File.respond_to? :realpath
+    def realpath file
+      File.realpath file
+    end
+  else
+    def realpath file
+      file
+    end
+  end
+
 end
 
 require 'rubygems/package/digest_io'
diff --git lib/rubygems/package/tar_header.rb lib/rubygems/package/tar_header.rb
index c54bd14d57..d557357114 100644
--- lib/rubygems/package/tar_header.rb
+++ lib/rubygems/package/tar_header.rb
@@ -104,25 +104,30 @@ def self.from(stream)
     fields = header.unpack UNPACK_FORMAT
 
     new :name     => fields.shift,
-        :mode     => fields.shift.oct,
-        :uid      => fields.shift.oct,
-        :gid      => fields.shift.oct,
-        :size     => fields.shift.oct,
-        :mtime    => fields.shift.oct,
-        :checksum => fields.shift.oct,
+        :mode     => strict_oct(fields.shift),
+        :uid      => strict_oct(fields.shift),
+        :gid      => strict_oct(fields.shift),
+        :size     => strict_oct(fields.shift),
+        :mtime    => strict_oct(fields.shift),
+        :checksum => strict_oct(fields.shift),
         :typeflag => fields.shift,
         :linkname => fields.shift,
         :magic    => fields.shift,
-        :version  => fields.shift.oct,
+        :version  => strict_oct(fields.shift),
         :uname    => fields.shift,
         :gname    => fields.shift,
-        :devmajor => fields.shift.oct,
-        :devminor => fields.shift.oct,
+        :devmajor => strict_oct(fields.shift),
+        :devminor => strict_oct(fields.shift),
         :prefix   => fields.shift,
 
         :empty => empty
   end
 
+  def self.strict_oct(str)
+    return str.oct if str =~ /\A[0-7]*\z/
+    raise ArgumentError, "#{str.inspect} is not an octal string"
+  end
+
   ##
   # Creates a new TarHeader using +vals+
 
diff --git lib/rubygems/package/tar_writer.rb lib/rubygems/package/tar_writer.rb
index f68b8d4c5e..390f7851a3 100644
--- lib/rubygems/package/tar_writer.rb
+++ lib/rubygems/package/tar_writer.rb
@@ -196,6 +196,8 @@ def add_file_signed name, mode, signer
       digest_name == signer.digest_name
     end
 
+    raise "no #{signer.digest_name} in #{digests.values.compact}" unless signature_digest
+
     if signer.key then
       signature = signer.sign signature_digest.digest
 
diff --git lib/rubygems/server.rb lib/rubygems/server.rb
index df4eb566d3..a7b5243ba0 100644
--- lib/rubygems/server.rb
+++ lib/rubygems/server.rb
@@ -631,6 +631,18 @@ def root(req, res)
       executables = nil if executables.empty?
       executables.last["is_last"] = true if executables
 
+      # Pre-process spec homepage for safety reasons
+      begin
+        homepage_uri = URI.parse(spec.homepage)
+        if [URI::HTTP, URI::HTTPS].member? homepage_uri.class
+          homepage_uri = spec.homepage
+        else
+          homepage_uri = "."
+        end
+      rescue URI::InvalidURIError
+        homepage_uri = "."
+      end
+
       specs << {
         "authors"             => spec.authors.sort.join(", "),
         "date"                => spec.date.to_s,
@@ -640,7 +652,7 @@ def root(req, res)
         "only_one_executable" => (executables && executables.size == 1),
         "full_name"           => spec.full_name,
         "has_deps"            => !deps.empty?,
-        "homepage"            => spec.homepage,
+        "homepage"            => homepage_uri,
         "name"                => spec.name,
         "rdoc_installed"      => Gem::RDoc.new(spec).rdoc_installed?,
         "ri_installed"        => Gem::RDoc.new(spec).ri_installed?,
diff --git lib/rubygems/specification.rb lib/rubygems/specification.rb
index 40e3a70d47..0a154b9001 100644
--- lib/rubygems/specification.rb
+++ lib/rubygems/specification.rb
@@ -15,6 +15,7 @@
 require 'rubygems/stub_specification'
 require 'rubygems/util/list'
 require 'stringio'
+require 'uri'
 
 ##
 # The Specification class contains the information for a Gem.  Typically
@@ -2813,10 +2814,16 @@ def validate packaging = true
       raise Gem::InvalidSpecificationException, "#{lazy} is not a summary"
     end
 
-    if homepage and not homepage.empty? and
-       homepage !~ /\A[a-z][a-z\d+.-]*:/i then
-      raise Gem::InvalidSpecificationException,
-            "\"#{homepage}\" is not a URI"
+    # Make sure a homepage is valid HTTP/HTTPS URI
+    if homepage and not homepage.empty?
+      begin
+        homepage_uri = URI.parse(homepage)
+        unless [URI::HTTP, URI::HTTPS].member? homepage_uri.class
+          raise Gem::InvalidSpecificationException, "\"#{homepage}\" is not a valid HTTP URI"
+        end
+      rescue URI::InvalidURIError
+        raise Gem::InvalidSpecificationException, "\"#{homepage}\" is not a valid HTTP URI"
+      end
     end
 
     # Warnings
diff --git test/rubygems/test_gem_commands_owner_command.rb test/rubygems/test_gem_commands_owner_command.rb
index 44652c1093..53cac4ce87 100644
--- test/rubygems/test_gem_commands_owner_command.rb
+++ test/rubygems/test_gem_commands_owner_command.rb
@@ -43,6 +43,31 @@ def test_show_owners
     assert_match %r{- 4}, @ui.output
   end
 
+  def test_show_owners_dont_load_objects
+    skip "testing a psych-only API" unless defined?(::Psych::DisallowedClass)
+
+    response = <<EOF
+---
+- email: !ruby/object:Object {}
+  id: 1
+  handle: user1
+- email: user2@example.com
+- id: 3
+  handle: user3
+- id: 4
+EOF
+
+    @fetcher.data["#{Gem.host}/api/v1/gems/freewill/owners.yaml"] = [response, 200, 'OK']
+
+    assert_raises Psych::DisallowedClass do
+      use_ui @ui do
+        @cmd.show_owners("freewill")
+      end
+    end
+
+  end
+
+
   def test_show_owners_setting_up_host_through_env_var
     response = "- email: user1@example.com\n"
     host = "http://rubygems.example"
diff --git test/rubygems/test_gem_package.rb test/rubygems/test_gem_package.rb
index 9d47f0dea4..5b93475314 100644
--- test/rubygems/test_gem_package.rb
+++ test/rubygems/test_gem_package.rb
@@ -455,6 +455,31 @@ def test_extract_tar_gz_symlink_relative_path
                  File.read(extracted)
   end
 
+  def test_extract_symlink_parent
+   skip 'symlink not supported' if Gem.win_platform?
+
+   package = Gem::Package.new @gem
+
+   tgz_io = util_tar_gz do |tar|
+     tar.mkdir       'lib',               0755
+     tar.add_symlink 'lib/link', '../..', 0644
+     tar.add_file    'lib/link/outside.txt', 0644 do |io| io.write 'hi' end
+   end
+
+   # Extract into a subdirectory of @destination; if this test fails it writes
+   # a file outside destination_subdir, but we want the file to remain inside
+   # @destination so it will be cleaned up.
+   destination_subdir = File.join @destination, 'subdir'
+   FileUtils.mkdir_p destination_subdir
+
+   e = assert_raises Gem::Package::PathError do
+     package.extract_tar_gz tgz_io, destination_subdir
+   end
+
+   assert_equal("installing into parent path lib/link/outside.txt of " +
+                 "#{destination_subdir} is not allowed", e.message)
+  end
+
   def test_extract_tar_gz_directory
     package = Gem::Package.new @gem
 
@@ -566,6 +591,21 @@ def test_install_location_relative
                  "#{@destination} is not allowed", e.message)
   end
 
+  def test_install_location_suffix
+    package = Gem::Package.new @gem
+
+    filename = "../#{File.basename(@destination)}suffix.rb"
+
+    e = assert_raises Gem::Package::PathError do
+      package.install_location filename, @destination
+    end
+
+    parent = File.expand_path File.join @destination, filename
+
+    assert_equal("installing into parent path #{parent} of " +
+                 "#{@destination} is not allowed", e.message)
+  end
+
   def test_load_spec
     entry = StringIO.new Gem.gzip @spec.to_yaml
     def entry.full_name() 'metadata.gz' end
@@ -723,6 +763,32 @@ def test_verify_nonexistent
     assert_match %r%nonexistent.gem$%,           e.message
   end
 
+  def test_verify_duplicate_file
+    FileUtils.mkdir_p 'lib'
+    FileUtils.touch 'lib/code.rb'
+
+    build = Gem::Package.new @gem
+    build.spec = @spec
+    build.setup_signer
+    open @gem, 'wb' do |gem_io|
+      Gem::Package::TarWriter.new gem_io do |gem|
+        build.add_metadata gem
+        build.add_contents gem
+
+        gem.add_file_simple 'a.sig', 0444, 0
+        gem.add_file_simple 'a.sig', 0444, 0
+      end
+    end
+
+    package = Gem::Package.new @gem
+
+    e = assert_raises Gem::Security::Exception do
+      package.verify
+    end
+
+    assert_equal 'duplicate files in the package: ("a.sig")', e.message
+  end
+
   def test_verify_security_policy
     skip 'openssl is missing' unless defined?(OpenSSL::SSL)
 
@@ -780,7 +846,13 @@ def test_verify_security_policy_checksum_missing
 
         # write bogus data.tar.gz to foil signature
         bogus_data = Gem.gzip 'hello'
-        gem.add_file_simple 'data.tar.gz', 0444, bogus_data.length do |io|
+        fake_signer = Class.new do
+          def digest_name; 'SHA512'; end
+          def digest_algorithm; Digest(:SHA512); end
+          def key; 'key'; end
+          def sign(*); 'fake_sig'; end
+        end
+        gem.add_file_signed 'data2.tar.gz', 0444, fake_signer.new do |io|
           io.write bogus_data
         end
 
diff --git test/rubygems/test_gem_package_tar_header.rb test/rubygems/test_gem_package_tar_header.rb
index d33877057d..43f508df45 100644
--- test/rubygems/test_gem_package_tar_header.rb
+++ test/rubygems/test_gem_package_tar_header.rb
@@ -143,5 +143,26 @@ def test_update_checksum
     assert_equal '012467', @tar_header.checksum
   end
 
+  def test_from_bad_octal
+    test_cases = [
+      "00000006,44\000", # bogus character
+      "00000006789\000", # non-octal digit
+      "+0000001234\000", # positive sign
+      "-0000001000\000", # negative sign
+      "0x000123abc\000", # radix prefix
+    ]
+
+    test_cases.each do |val|
+      header_s = @tar_header.to_s
+      # overwrite the size field
+      header_s[124, 12] = val
+      io = TempIO.new header_s
+      assert_raises ArgumentError do
+        new_header = Gem::Package::TarHeader.from io
+      end
+      io.close! if io.respond_to? :close!
+    end
+  end
+
 end
 
diff --git test/rubygems/test_gem_server.rb test/rubygems/test_gem_server.rb
index 4873fac5b6..96ed9194e9 100644
--- test/rubygems/test_gem_server.rb
+++ test/rubygems/test_gem_server.rb
@@ -336,6 +336,171 @@ def test_root_gemdirs
     assert_match 'z 9', @res.body
   end
 
+
+  def test_xss_homepage_fix_289313
+    data = StringIO.new "GET / HTTP/1.0\r\n\r\n"
+    dir = "#{@gemhome}2"
+
+    spec = util_spec 'xsshomepagegem', 1
+    spec.homepage = "javascript:confirm(document.domain)"
+
+    specs_dir = File.join dir, 'specifications'
+    FileUtils.mkdir_p specs_dir
+
+    open File.join(specs_dir, spec.spec_name), 'w' do |io|
+      io.write spec.to_ruby
+    end
+
+    server = Gem::Server.new dir, process_based_port, false
+
+    @req.parse data
+
+    server.root @req, @res
+
+    assert_equal 200, @res.status
+    assert_match 'xsshomepagegem 1', @res.body
+
+    # This verifies that the homepage for this spec is not displayed and is set to ".", because it's not a 
+    # valid HTTP/HTTPS URL and could be unsafe in an HTML context.  We would prefer to throw an exception here,
+    # but spec.homepage is currently free form and not currently required to be a URL, this behavior may be 
+    # validated in future versions of Gem::Specification.
+    #
+    # There are two variant we're checking here, one where rdoc is not present, and one where rdoc is present in the same regex:
+    #
+    # Variant #1 - rdoc not installed
+    #
+    #   <b>xsshomepagegem 1</b>
+    #
+    #
+    #  <span title="rdoc not installed">[rdoc]</span>
+    #
+    #
+    #
+    #  <a href="." title=".">[www]</a>
+    #
+    # Variant #2 - rdoc installed
+    #
+    #   <b>xsshomepagegem 1</b>
+    #
+    #
+    #  <a href="\/doc_root\/xsshomepagegem-1\/">\[rdoc\]<\/a>
+    #
+    #
+    #
+    #  <a href="." title=".">[www]</a>
+    regex_match = /xsshomepagegem 1<\/b>[\n\s]+(<span title="rdoc not installed">\[rdoc\]<\/span>|<a href="\/doc_root\/xsshomepagegem-1\/">\[rdoc\]<\/a>)[\n\s]+<a href="\." title="\.">\[www\]<\/a>/
+    assert_match regex_match, @res.body
+  end
+
+  def test_invalid_homepage
+    data = StringIO.new "GET / HTTP/1.0\r\n\r\n"
+    dir = "#{@gemhome}2"
+
+    spec = util_spec 'invalidhomepagegem', 1
+    spec.homepage = "notavalidhomepageurl"
+
+    specs_dir = File.join dir, 'specifications'
+    FileUtils.mkdir_p specs_dir
+
+    open File.join(specs_dir, spec.spec_name), 'w' do |io|
+      io.write spec.to_ruby
+    end
+
+    server = Gem::Server.new dir, process_based_port, false
+
+    @req.parse data
+
+    server.root @req, @res
+
+    assert_equal 200, @res.status
+    assert_match 'invalidhomepagegem 1', @res.body
+
+    # This verifies that the homepage for this spec is not displayed and is set to ".", because it's not a 
+    # valid HTTP/HTTPS URL and could be unsafe in an HTML context.  We would prefer to throw an exception here,
+    # but spec.homepage is currently free form and not currently required to be a URL, this behavior may be 
+    # validated in future versions of Gem::Specification.
+    #
+    # There are two variant we're checking here, one where rdoc is not present, and one where rdoc is present in the same regex:
+    #
+    # Variant #1 - rdoc not installed
+    #
+    #   <b>invalidhomepagegem 1</b>
+    #
+    #
+    #  <span title="rdoc not installed">[rdoc]</span>
+    #
+    #
+    #
+    #  <a href="." title=".">[www]</a>
+    #
+    # Variant #2 - rdoc installed
+    #
+    #   <b>invalidhomepagegem 1</b>
+    #
+    #
+    #  <a href="\/doc_root\/invalidhomepagegem-1\/">\[rdoc\]<\/a>
+    #
+    #
+    #
+    #  <a href="." title=".">[www]</a>
+    regex_match = /invalidhomepagegem 1<\/b>[\n\s]+(<span title="rdoc not installed">\[rdoc\]<\/span>|<a href="\/doc_root\/invalidhomepagegem-1\/">\[rdoc\]<\/a>)[\n\s]+<a href="\." title="\.">\[www\]<\/a>/
+    assert_match regex_match, @res.body
+  end
+
+  def test_valid_homepage_http
+    data = StringIO.new "GET / HTTP/1.0\r\n\r\n"
+    dir = "#{@gemhome}2"
+
+    spec = util_spec 'validhomepagegemhttp', 1
+    spec.homepage = "http://rubygems.org"
+
+    specs_dir = File.join dir, 'specifications'
+    FileUtils.mkdir_p specs_dir
+
+    open File.join(specs_dir, spec.spec_name), 'w' do |io|
+      io.write spec.to_ruby
+    end
+
+    server = Gem::Server.new dir, process_based_port, false
+
+    @req.parse data
+
+    server.root @req, @res
+
+    assert_equal 200, @res.status
+    assert_match 'validhomepagegemhttp 1', @res.body
+
+    regex_match = /validhomepagegemhttp 1<\/b>[\n\s]+(<span title="rdoc not installed">\[rdoc\]<\/span>|<a href="\/doc_root\/validhomepagegemhttp-1\/">\[rdoc\]<\/a>)[\n\s]+<a href="http:\/\/rubygems\.org" title="http:\/\/rubygems\.org">\[www\]<\/a>/
+    assert_match regex_match, @res.body
+  end
+
+  def test_valid_homepage_https
+    data = StringIO.new "GET / HTTP/1.0\r\n\r\n"
+    dir = "#{@gemhome}2"
+
+    spec = util_spec 'validhomepagegemhttps', 1
+    spec.homepage = "https://rubygems.org"
+
+    specs_dir = File.join dir, 'specifications'
+    FileUtils.mkdir_p specs_dir
+
+    open File.join(specs_dir, spec.spec_name), 'w' do |io|
+      io.write spec.to_ruby
+    end
+
+    server = Gem::Server.new dir, process_based_port, false
+
+    @req.parse data
+
+    server.root @req, @res
+
+    assert_equal 200, @res.status
+    assert_match 'validhomepagegemhttps 1', @res.body
+
+    regex_match = /validhomepagegemhttps 1<\/b>[\n\s]+(<span title="rdoc not installed">\[rdoc\]<\/span>|<a href="\/doc_root\/validhomepagegemhttps-1\/">\[rdoc\]<\/a>)[\n\s]+<a href="https:\/\/rubygems\.org" title="https:\/\/rubygems\.org">\[www\]<\/a>/
+    assert_match regex_match, @res.body
+  end
+
   def test_specs
     data = StringIO.new "GET /specs.#{Gem.marshal_version} HTTP/1.0\r\n\r\n"
     @req.parse data
diff --git test/rubygems/test_gem_specification.rb test/rubygems/test_gem_specification.rb
index 0fcc11e78f..1c68826fb3 100644
--- test/rubygems/test_gem_specification.rb
+++ test/rubygems/test_gem_specification.rb
@@ -2890,7 +2890,22 @@ def test_validate_homepage
         @a1.validate
       end
 
-      assert_equal '"over at my cool site" is not a URI', e.message
+      assert_equal '"over at my cool site" is not a valid HTTP URI', e.message
+
+      @a1.homepage = 'ftp://rubygems.org'
+
+      e = assert_raises Gem::InvalidSpecificationException do
+        @a1.validate
+      end
+
+      assert_equal '"ftp://rubygems.org" is not a valid HTTP URI', e.message
+
+      @a1.homepage = 'http://rubygems.org'
+      assert_equal true, @a1.validate
+
+      @a1.homepage = 'https://rubygems.org'
+      assert_equal true, @a1.validate
+
     end
   end