diff --git a/src/backend/utils/adt/xml.c b/src/backend/utils/adt/xml.c
index e96eec6da8..423bef220a 100644
--- a/src/backend/utils/adt/xml.c
+++ b/src/backend/utils/adt/xml.c
@@ -48,6 +48,7 @@
 #ifdef USE_LIBXML
 #include <libxml/chvalid.h>
 #include <libxml/parser.h>
+#include <libxml/parserInternals.h>
 #include <libxml/tree.h>
 #include <libxml/uri.h>
 #include <libxml/xmlerror.h>
@@ -86,6 +87,8 @@ XmlOptionType xmloption;
 
 static StringInfo xml_err_buf = NULL;
 
+static xmlParserInputPtr xmlPgEntityLoader(const char *URL, const char *ID,
+				  xmlParserCtxtPtr ctxt);
 static void xml_errorHandler(void *ctxt, const char *msg,...);
 static void xml_ereport_by_code(int level, int sqlcode,
 					const char *msg, int errcode);
@@ -923,6 +926,9 @@ pg_xml_init(void)
 		/* Now that xml_err_buf exists, safe to call xml_errorHandler */
 		xmlSetGenericErrorFunc(NULL, xml_errorHandler);
 
+		/* set up our entity loader, too */
+		xmlSetExternalEntityLoader(xmlPgEntityLoader);
+
 #ifdef USE_LIBXMLCONTEXT
 		/* Set up memory allocation our way, too */
 		xml_memory_init();
@@ -947,6 +953,9 @@ pg_xml_init(void)
 		 * about, anyway.
 		 */
 		xmlSetGenericErrorFunc(NULL, xml_errorHandler);
+
+		/* set up our entity loader, too */
+		xmlSetExternalEntityLoader(xmlPgEntityLoader);
 	}
 }
 
@@ -1366,6 +1375,25 @@ xml_pstrdup(const char *string)
 #endif   /* USE_LIBXMLCONTEXT */
 
 
+/*
+ * xmlPgEntityLoader --- entity loader callback function
+ *
+ * Silently prevent any external entity URL from being loaded.  We don't want
+ * to throw an error, so instead make the entity appear to expand to an empty
+ * string.
+ *
+ * We would prefer to allow loading entities that exist in the system's
+ * global XML catalog; but the available libxml2 APIs make that a complex
+ * and fragile task.  For now, just shut down all external access.
+ */
+static xmlParserInputPtr
+xmlPgEntityLoader(const char *URL, const char *ID,
+				  xmlParserCtxtPtr ctxt)
+{
+	return xmlNewStringInputStream(ctxt, (const xmlChar *) "");
+}
+
+
 /*
  * xml_ereport --- report an XML-related error
  *
diff --git a/src/test/regress/expected/xml.out b/src/test/regress/expected/xml.out
index 3bfefcd9f9..a3e0ff00fd 100644
--- a/src/test/regress/expected/xml.out
+++ b/src/test/regress/expected/xml.out
@@ -467,3 +467,23 @@ SELECT xpath('//b', '<a>one <b>two</b> three <b>etc</b></a>');
  {<b>two</b>,<b>etc</b>}
 (1 row)
 
+-- External entity references should not leak filesystem information.
+SELECT XMLPARSE(DOCUMENT '<!DOCTYPE foo [<!ENTITY c SYSTEM "/etc/passwd">]><foo>&c;</foo>');
+                            xmlparse                             
+-----------------------------------------------------------------
+ <!DOCTYPE foo [<!ENTITY c SYSTEM "/etc/passwd">]><foo>&c;</foo>
+(1 row)
+
+SELECT XMLPARSE(DOCUMENT '<!DOCTYPE foo [<!ENTITY c SYSTEM "/etc/no.such.file">]><foo>&c;</foo>');
+                               xmlparse                                
+-----------------------------------------------------------------------
+ <!DOCTYPE foo [<!ENTITY c SYSTEM "/etc/no.such.file">]><foo>&c;</foo>
+(1 row)
+
+-- This might or might not load the requested DTD, but it mustn't throw error.
+SELECT XMLPARSE(DOCUMENT '<!DOCTYPE chapter PUBLIC "-//OASIS//DTD DocBook XML V4.1.2//EN" "http://www.oasis-open.org/docbook/xml/4.1.2/docbookx.dtd"><chapter>&nbsp;</chapter>');
+                                                                       xmlparse                                                                       
+------------------------------------------------------------------------------------------------------------------------------------------------------
+ <!DOCTYPE chapter PUBLIC "-//OASIS//DTD DocBook XML V4.1.2//EN" "http://www.oasis-open.org/docbook/xml/4.1.2/docbookx.dtd"><chapter>&nbsp;</chapter>
+(1 row)
+
diff --git a/src/test/regress/expected/xml_1.out b/src/test/regress/expected/xml_1.out
index d6a7c31e93..a4a12e1423 100644
--- a/src/test/regress/expected/xml_1.out
+++ b/src/test/regress/expected/xml_1.out
@@ -376,3 +376,17 @@ SELECT xpath('//b', '<a>one <b>two</b> three <b>etc</b></a>');
 ERROR:  unsupported XML feature
 DETAIL:  This functionality requires the server to be built with libxml support.
 HINT:  You need to rebuild PostgreSQL using --with-libxml.
+-- External entity references should not leak filesystem information.
+SELECT XMLPARSE(DOCUMENT '<!DOCTYPE foo [<!ENTITY c SYSTEM "/etc/passwd">]><foo>&c;</foo>');
+ERROR:  unsupported XML feature
+DETAIL:  This functionality requires the server to be built with libxml support.
+HINT:  You need to rebuild PostgreSQL using --with-libxml.
+SELECT XMLPARSE(DOCUMENT '<!DOCTYPE foo [<!ENTITY c SYSTEM "/etc/no.such.file">]><foo>&c;</foo>');
+ERROR:  unsupported XML feature
+DETAIL:  This functionality requires the server to be built with libxml support.
+HINT:  You need to rebuild PostgreSQL using --with-libxml.
+-- This might or might not load the requested DTD, but it mustn't throw error.
+SELECT XMLPARSE(DOCUMENT '<!DOCTYPE chapter PUBLIC "-//OASIS//DTD DocBook XML V4.1.2//EN" "http://www.oasis-open.org/docbook/xml/4.1.2/docbookx.dtd"><chapter>&nbsp;</chapter>');
+ERROR:  unsupported XML feature
+DETAIL:  This functionality requires the server to be built with libxml support.
+HINT:  You need to rebuild PostgreSQL using --with-libxml.
diff --git a/src/test/regress/sql/xml.sql b/src/test/regress/sql/xml.sql
index edf639b8c5..f6208fb4a8 100644
--- a/src/test/regress/sql/xml.sql
+++ b/src/test/regress/sql/xml.sql
@@ -158,3 +158,9 @@ SELECT xpath('', '<!-- error -->');
 SELECT xpath('//text()', '<local:data xmlns:local="http://127.0.0.1"><local:piece id="1">number one</local:piece><local:piece id="2" /></local:data>');
 SELECT xpath('//loc:piece/@id', '<local:data xmlns:local="http://127.0.0.1"><local:piece id="1">number one</local:piece><local:piece id="2" /></local:data>', ARRAY[ARRAY['loc', 'http://127.0.0.1']]);
 SELECT xpath('//b', '<a>one <b>two</b> three <b>etc</b></a>');
+
+-- External entity references should not leak filesystem information.
+SELECT XMLPARSE(DOCUMENT '<!DOCTYPE foo [<!ENTITY c SYSTEM "/etc/passwd">]><foo>&c;</foo>');
+SELECT XMLPARSE(DOCUMENT '<!DOCTYPE foo [<!ENTITY c SYSTEM "/etc/no.such.file">]><foo>&c;</foo>');
+-- This might or might not load the requested DTD, but it mustn't throw error.
+SELECT XMLPARSE(DOCUMENT '<!DOCTYPE chapter PUBLIC "-//OASIS//DTD DocBook XML V4.1.2//EN" "http://www.oasis-open.org/docbook/xml/4.1.2/docbookx.dtd"><chapter>&nbsp;</chapter>');