diff -Nur libgd2-2.0.33/gd_gif_in.c libgd2-2.0.33.new/gd_gif_in.c
--- libgd2-2.0.33/gd_gif_in.c	2004-11-01 19:28:56.000000000 +0100
+++ libgd2-2.0.33.new/gd_gif_in.c	2006-06-13 11:28:31.000000000 +0200
@@ -118,6 +118,7 @@
        char            version[4];
        /* 2.0.28: threadsafe storage */
        int ZeroDataBlock = FALSE;
+       int             maxcount = 1024;
 
        gdImagePtr im = 0;
        if (! ReadOK(fd,buf,6)) {
@@ -164,6 +165,8 @@
                }
 
                if (c != ',') {         /* Not a valid start character */
+		       if (--maxcount < 0)
+			       goto terminated;  /* Looping */
                        continue;
                }
 
@@ -242,6 +245,7 @@
 DoExtension(gdIOCtx *fd, int label, int *Transparent, int *ZeroDataBlockP)
 {
        static unsigned char     buf[256];
+       int                      maxcount = 1024;
 
        switch (label) {
        case 0xf9:              /* Graphic Control Extension */
@@ -254,13 +258,13 @@
                if ((buf[0] & 0x1) != 0)
                        *Transparent = buf[3];
 
-               while (GetDataBlock(fd, (unsigned char*) buf, ZeroDataBlockP) != 0)
+               while (GetDataBlock(fd, (unsigned char*) buf, ZeroDataBlockP) != 0 && --maxcount >= 0)
                        ;
                return FALSE;
        default:
                break;
        }
-       while (GetDataBlock(fd, (unsigned char*) buf, ZeroDataBlockP) != 0)
+       while (GetDataBlock(fd, (unsigned char*) buf, ZeroDataBlockP) != 0 && --maxcount >= 0)
                ;
 
        return FALSE;
@@ -419,14 +423,15 @@
                } else if (code == end_code) {
                        int             count;
                        unsigned char   buf[260];
+		       int             maxcount = 1024;
 
                        if (*ZeroDataBlockP)
                                return -2;
 
-                       while ((count = GetDataBlock(fd, buf, ZeroDataBlockP)) > 0)
+                       while ((count = GetDataBlock(fd, buf, ZeroDataBlockP)) > 0  && --maxcount >= 0)
                                ;
 
-                       if (count != 0)
+                       if (count != 0 || maxcount < 0)
                        return -2;
                }