diff --git a/xmlsecurity/source/helper/ooxmlsecparser.cxx b/xmlsecurity/source/helper/ooxmlsecparser.cxx
index da2ed2c0f9b6..2086d3876283 100644
--- a/xmlsecurity/source/helper/ooxmlsecparser.cxx
+++ b/xmlsecurity/source/helper/ooxmlsecparser.cxx
@@ -20,6 +20,7 @@ OOXMLSecParser::OOXMLSecParser(XSecController* pXSecController)
     ,m_bInMdssiValue(false)
     ,m_bInSignatureComments(false)
     ,m_bInX509IssuerName(false)
+    ,m_bInX509SerialNumber(false)
     ,m_bReferenceUnresolved(false)
 {
 }
@@ -106,6 +107,11 @@ throw (xml::sax::SAXException, uno::RuntimeException, std::exception)
         m_aX509IssuerName.clear();
         m_bInX509IssuerName = true;
     }
+    else if (rName == "X509SerialNumber")
+    {
+        m_aX509SerialNumber.clear();
+        m_bInX509SerialNumber = true;
+    }
 
     if (m_xNextHandler.is())
         m_xNextHandler->startElement(rName, xAttribs);
@@ -152,6 +158,11 @@ void SAL_CALL OOXMLSecParser::endElement(const OUString& rName) throw (xml::sax:
         m_pXSecController->setX509IssuerName(m_aX509IssuerName);
         m_bInX509IssuerName = false;
     }
+    else if (rName == "X509SerialNumber")
+    {
+        m_pXSecController->setX509SerialNumber(m_aX509SerialNumber);
+        m_bInX509SerialNumber = false;
+    }
 
     if (m_xNextHandler.is())
         m_xNextHandler->endElement(rName);
@@ -171,6 +182,8 @@ void SAL_CALL OOXMLSecParser::characters(const OUString& rChars) throw (xml::sax
         m_aSignatureComments += rChars;
     else if (m_bInX509IssuerName)
         m_aX509IssuerName += rChars;
+    else if (m_bInX509SerialNumber)
+        m_aX509SerialNumber += rChars;
 
     if (m_xNextHandler.is())
         m_xNextHandler->characters(rChars);
diff --git a/xmlsecurity/source/helper/ooxmlsecparser.hxx b/xmlsecurity/source/helper/ooxmlsecparser.hxx
index 1914d4ca50fd..819947baff8a 100644
--- a/xmlsecurity/source/helper/ooxmlsecparser.hxx
+++ b/xmlsecurity/source/helper/ooxmlsecparser.hxx
@@ -41,6 +41,8 @@ class OOXMLSecParser: public cppu::WeakImplHelper
     OUString m_aSignatureComments;
     bool m_bInX509IssuerName;
     OUString m_aX509IssuerName;
+    bool m_bInX509SerialNumber;
+    OUString m_aX509SerialNumber;
 
     /// Last seen <Reference URI="...">.
     OUString m_aReferenceURI;