diff --git a/debian/patches/0006-Limit-depth-of-group-embedding.patch b/debian/patches/0006-Limit-depth-of-group-embedding.patch
new file mode 100644
index 0000000..24c7ff2
--- /dev/null
+++ b/debian/patches/0006-Limit-depth-of-group-embedding.patch
@@ -0,0 +1,107 @@
+Description: Limit depth of group embedding
+ Limit depth of group embedding to guard against malicious files with
+ thousands of consecutive {
+Origin: backport, http://hg.savannah.gnu.org/hgweb/unrtf/raw-rev/7d7f30c53ca0
+Forwarded: not-needed
+Author: Salvatore Bonaccorso <carnil@debian.org>
+Last-Update: 2015-01-26
+Applied-Upstream: 0.21.7
+
+--- a/src/convert.c
++++ b/src/convert.c
+@@ -3075,7 +3075,7 @@ accumulate_iconv_input(int ch)
+  *=======================================================================*/
+ 
+ static void
+-word_print_core (Word *w)
++word_print_core (Word *w, int groupdepth)
+ {
+ 	char *s;
+ 	char *alias;
+@@ -3084,6 +3084,10 @@ word_print_core (Word *w)
+ 	int paragraph_begined=FALSE;
+ 	int paragraph_align=ALIGN_LEFT;
+ 
++        if (groupdepth > MAX_GROUP_DEPTH) {
++		warning_handler ("Max group depth reached");
++		return;
++        }
+ 	CHECK_PARAM_NOT_NULL(w);
+ 
+ 	if (!coming_pars_that_are_tabular && within_table) {
+@@ -3378,7 +3382,7 @@ word_print_core (Word *w)
+ 			}
+ 
+ 			if (child) 
+-			  word_print_core (child);
++                            word_print_core (child, groupdepth+1);
+ 		}
+ 
+ 		if (w) 
+@@ -3457,7 +3461,7 @@ word_print (Word *w)
+ 	have_printed_body=FALSE;
+ 	within_table=FALSE;
+ 	simulate_allcaps=FALSE;
+-	word_print_core (w);
++	word_print_core (w, 1);
+ 	end_table();
+ 
+ 	if (!inline_mode) {
+--- a/src/main.c
++++ b/src/main.c
+@@ -263,7 +263,7 @@ main (int argc, char **argv)
+ 		printf("\n");
+ 	} else {
+ /* Should we also optimize word before dump? - AF */
+-		word = optimize_word(word);
++		word = optimize_word(word, 1);
+ 		word_print(word);
+ 	}
+ 
+--- a/src/word.c
++++ b/src/word.c
+@@ -222,7 +222,7 @@ word_dump (Word *w)
+  * Returns:	Optimized word.
+  *=======================================================================*/
+ Word *
+-optimize_word(Word *w)
++optimize_word(Word *w, int depth)
+ {
+ 	char *s, *s1;
+ 	int i = 0, len;
+@@ -230,6 +230,11 @@ optimize_word(Word *w)
+ 	Tag tags_to_opt[] = OPT_ARRAY;
+ 	Word *root = w, *w2;
+ 
++        if (depth > MAX_GROUP_DEPTH) {
++		/* Have to be reasonable at some point */
++		warning_handler ("Max group depth reached");
++		return w;
++        }
+ 	for (; w != NULL; w = w->next)
+ 	{
+ 
+@@ -264,7 +269,7 @@ optimize_word(Word *w)
+ 		}
+ 
+ 		if (w->child != NULL)
+-			w->child = optimize_word(w->child);
++			w->child = optimize_word(w->child, depth+1);
+ 
+ 		w2 = w;
+ 	}
+--- a/src/word.h
++++ b/src/word.h
+@@ -49,7 +49,11 @@ extern char* word_string (Word*);
+ extern void word_dump (Word*);
+ extern void word_print_html (Word*);
+ 
+-extern Word* optimize_word(Word*);
++#ifndef MAX_GROUP_DEPTH
++#define MAX_GROUP_DEPTH 1000
++#endif
++ 
++extern Word* optimize_word(Word*, int depth);
+ 
+ typedef struct _t {
+ 	char *name;
diff --git a/debian/patches/series b/debian/patches/series
index 29cff5e..0f09bbd 100644
--- a/debian/patches/series
+++ b/debian/patches/series
@@ -3,3 +3,4 @@
 0003-Fix-a-number-of-possible-crashes-caused-by-a-bad-for.patch
 0004-attrstack_drop-Properly-drop-the-last-stack-element.patch
 0005-attr_get_param-Silence-a-warning-message-again.patch
+0006-Limit-depth-of-group-embedding.patch