diff -Nrbu mailx-12.5/lzw.c mailx-12.5-OK/lzw.c

--- mailx-12.5/lzw.c	2006-03-04 03:32:16.000000000 +0300

+++ mailx-12.5-OK/lzw.c	2011-08-17 16:30:01.000000000 +0400

@@ -516,6 +516,8 @@

 		/* Generate output characters in reverse order. */

 		while (code >= 256) {

+			if (stackp - de_stack >= HSIZE - 1)

+				return -1;

 			*stackp++ = tab_suffixof(code);

 			code = tab_prefixof(code);

 		}