diff -Nru raptor2-2.0.15/debian/changelog raptor2-2.0.15/debian/changelog
--- raptor2-2.0.15/debian/changelog	2019-08-29 09:05:35.000000000 +0000
+++ raptor2-2.0.15/debian/changelog	2020-11-11 12:29:13.000000000 +0000
@@ -1,3 +1,12 @@
+raptor2 (2.0.15-0ubuntu1.20.04.1) focal-security; urgency=medium
+
+  * SECURITY UPDATE: heap-based overflow via nspace declarations
+    - debian/patches/CVE-2017-18926.patch: calcualte max nspace
+      declarations correctly for XML writer in src/raptor_xml_writer.c.
+    - CVE-2017-18926
+
+ -- Marc Deslauriers <marc.deslauriers@ubuntu.com>  Wed, 11 Nov 2020 07:29:13 -0500
+
 raptor2 (2.0.15-0ubuntu1) eoan; urgency=medium
 
   * New upstream version
diff -Nru raptor2-2.0.15/debian/patches/CVE-2017-18926.patch raptor2-2.0.15/debian/patches/CVE-2017-18926.patch
--- raptor2-2.0.15/debian/patches/CVE-2017-18926.patch	1970-01-01 00:00:00.000000000 +0000
+++ raptor2-2.0.15/debian/patches/CVE-2017-18926.patch	2020-11-11 12:29:10.000000000 +0000
@@ -0,0 +1,40 @@
+From 590681e546cd9aa18d57dc2ea1858cb734a3863f Mon Sep 17 00:00:00 2001
+From: Dave Beckett <dave@dajobe.org>
+Date: Sun, 16 Apr 2017 23:15:12 +0100
+Subject: [PATCH] Calcualte max nspace declarations correctly for XML writer
+
+(raptor_xml_writer_start_element_common): Calculate max including for
+each attribute a potential name and value.
+
+Fixes Issues #0000617 http://bugs.librdf.org/mantis/view.php?id=617
+and #0000618 http://bugs.librdf.org/mantis/view.php?id=618
+---
+ src/raptor_xml_writer.c | 7 ++++---
+ 1 file changed, 4 insertions(+), 3 deletions(-)
+
+diff --git a/src/raptor_xml_writer.c b/src/raptor_xml_writer.c
+index 693b9468..0d3a36a5 100644
+--- a/src/raptor_xml_writer.c
++++ b/src/raptor_xml_writer.c
+@@ -181,9 +181,10 @@ raptor_xml_writer_start_element_common(raptor_xml_writer* xml_writer,
+   size_t nspace_declarations_count = 0;  
+   unsigned int i;
+ 
+-  /* max is 1 per element and 1 for each attribute + size of declared */
+   if(nstack) {
+-    int nspace_max_count = element->attribute_count+1;
++    int nspace_max_count = element->attribute_count * 2; /* attr and value */
++    if(element->name->nspace)
++      nspace_max_count++;
+     if(element->declared_nspaces)
+       nspace_max_count += raptor_sequence_size(element->declared_nspaces);
+     if(element->xml_language)
+@@ -237,7 +238,7 @@ raptor_xml_writer_start_element_common(raptor_xml_writer* xml_writer,
+         }
+       }
+ 
+-      /* Add the attribute + value */
++      /* Add the attribute's value */
+       nspace_declarations[nspace_declarations_count].declaration=
+         raptor_qname_format_as_xml(element->attributes[i],
+                                    &nspace_declarations[nspace_declarations_count].length);
diff -Nru raptor2-2.0.15/debian/patches/series raptor2-2.0.15/debian/patches/series
--- raptor2-2.0.15/debian/patches/series	1970-01-01 00:00:00.000000000 +0000
+++ raptor2-2.0.15/debian/patches/series	2020-11-11 12:29:10.000000000 +0000
@@ -0,0 +1 @@
+CVE-2017-18926.patch