diff --git a/CVE-2021-28834.patch b/CVE-2021-28834.patch
new file mode 100644
index 0000000..72aaae6
--- /dev/null
+++ b/CVE-2021-28834.patch
@@ -0,0 +1,74 @@
+From 1690419eb9feacdf45afe362d21114c82051d7a4 Mon Sep 17 00:00:00 2001
+From: wang_yue111 <648774160@qq.com>
+Date: Mon, 29 Mar 2021 16:58:23 +0800
+Subject: [PATCH] Restrict Rouge formatters to Rouge::Formatters namespace
+
+ff0218a added support for specifying custom Rouge formatters with the
+constraint that the formatter be in theRouge::Formatters namespace, but
+it did not actually enforce this constraint. For example, this is valid:
+
+```ruby
+Rouge::Formatters.const_get('CSV')
+=> CSV
+```
+
+Adding the `false` parameter to `const_get` prevents this:
+
+```ruby
+Rouge::Formatters.const_get('CSV', false)
+NameError: uninitialized constant Rouge::Formatters::CSV
+```
+
+---
+ .../converter/syntax_highlighter/rouge.rb      |  2 +-
+ test/test_files.rb                             | 18 +++++++++++-------
+ 2 files changed, 12 insertions(+), 8 deletions(-)
+
+diff --git a/lib/kramdown/converter/syntax_highlighter/rouge.rb b/lib/kramdown/converter/syntax_highlighter/rouge.rb
+index 8ca55d8..94e8c97 100644
+--- a/lib/kramdown/converter/syntax_highlighter/rouge.rb
++++ b/lib/kramdown/converter/syntax_highlighter/rouge.rb
+@@ -62,7 +62,7 @@ module Kramdown::Converter::SyntaxHighlighter
+       when Class
+         formatter
+       when /\A[[:upper:]][[:alnum:]_]*\z/
+-        ::Rouge::Formatters.const_get(formatter)
++        ::Rouge::Formatters.const_get(formatter, false)
+       else
+         # Available in Rouge 2.0 or later
+         ::Rouge::Formatters::HTMLLegacy
+diff --git a/test/test_files.rb b/test/test_files.rb
+index d788115..3a7bd74 100644
+--- a/test/test_files.rb
++++ b/test/test_files.rb
+@@ -20,16 +20,20 @@ begin
+   end
+ 
+   # custom formatter for tests
+-  class RougeHTMLFormatters < Kramdown::Converter::SyntaxHighlighter::Rouge.formatter_class
++  module Rouge
++    module Formatters
++      class RougeHTMLFormatters < Kramdown::Converter::SyntaxHighlighter::Rouge.formatter_class
+ 
+-    tag 'rouge_html_formatters'
++        tag 'rouge_html_formatters'
+ 
+-    def stream(tokens, &b)
+-      yield %(<div class="custom-class">)
+-      super
+-      yield %(</div>)
+-    end
++        def stream(tokens, &b)
++          yield %(<div class="custom-class">)
++          super
++          yield %(</div>)
++        end
+ 
++      end
++    end
+   end
+ rescue LoadError, SyntaxError, NameError
+ end
+-- 
+2.23.0
+
diff --git a/rubygem-kramdown.spec b/rubygem-kramdown.spec
index 5bfed2b..9d4ca77 100644
--- a/rubygem-kramdown.spec
+++ b/rubygem-kramdown.spec
@@ -1,11 +1,12 @@
 %global gem_name kramdown
 Name:                rubygem-%{gem_name}
 Version:             2.1.0
-Release:             1
+Release:             2
 Summary:             A fast pure Ruby yet-another-markdown-parser
 License:             MIT
 URL:                 http://kramdown.rubyforge.org
 Source0:             https://rubygems.org/gems/%{gem_name}-%{version}.gem
+Patch0000:           CVE-2021-28834.patch
 BuildRequires:       ruby(release) rubygems-devel rubygem(minitest) >= 5 rubygem(rouge)
 BuildRequires:       rubygem(test-unit) tidy tex tex(acronym.sty) tex(amssymb.sty)
 BuildRequires:       tex(amsmath.sty) tex(amsthm.sty) tex(amsfonts.sty) tex(utf8x.def) tex-ec
@@ -28,7 +29,7 @@ Documentation for %{name}
 
 %prep
 gem unpack %{SOURCE0}
-%autosetup -D -T -n kramdown-%{version}
+%autosetup -D -T -n kramdown-%{version} -p1
 gem spec %{SOURCE0} -l --ruby > kramdown.gemspec
 
 %build
@@ -83,6 +84,9 @@ popd
 %doc %{gem_docdir}
 
 %changelog
+* Mon Mar 29 2021 wangyue <wangyue92@huawei.com> - 2.1.0-2
+- fix CVE-2021-28834
+
 * Tue Dec 15 2020 chengzihan <chengzihan2@huawei.com> - 2.1.0-1
 - update to 2.1.0