This patch is taken from upstream and modified to adjust our currently
released version.

From 99eda421f7ddc27b14e4ac1d2126e5fe41719081 Mon Sep 17 00:00:00 2001
From: "Emden R. Gansner" <[email protected]>
Date: Mon, 24 Nov 2014 14:32:58 -0500
Subject: [PATCH] Fix format string vulnerability in using agerr() to report
 errors during parsing. We now use a fixed format %s, and pass the error
 string as an argument.

---
 lib/cgraph/scan.l | 3 ++-
 1 file changed, 2 insertions(+), 1 deletion(-)

diff --git a/lib/cgraph/scan.l b/lib/cgraph/scan.l
index 85a150a..a5872f4 100644
--- a/lib/cgraph/scan.l
+++ b/lib/cgraph/scan.l
@@ -225,6 +225,7 @@ ID		({NAME}|{NUMBER})
 <hstring>([^><\n]*)		addstr(yytext);
 .						return (yytext[0]);
 %%
+ 
 void yyerror(char *str)
 {
 	unsigned char	xbuf[BUFSIZ];
@@ -273,7 +274,7 @@ void yyerror(char *str)
	agxbput (&xb, yytext);
	agxbput (&xb,"'\n");
-	agerr(AGWARN,agxbuse(&xb));
+	agerr(AGWARN, "%s", agxbuse(&xb));
 	agxbfree(&xb);
 }
 /* must be here to see flex's macro defns */