Apply by doing:
       cd /usr/src
       patch -p0 < 026_talkd.patch
       cd libexec/talkd
       make obj && make depend && make && make install

Index: libexec/talkd/announce.c
===================================================================
RCS file: /cvs/src/libexec/talkd/announce.c,v
retrieving revision 1.8
retrieving revision 1.9
diff -u -r1.8 -r1.9
--- libexec/talkd/announce.c    1998/08/18 03:42:10     1.8
+++ libexec/talkd/announce.c    2000/07/06 00:01:45     1.9
@@ -160,6 +160,6 @@
               *(bptr++) = '\n';
       }
       *bptr = '\0';
-       fprintf(tf, big_buf);
+       fprintf(tf, "%s", big_buf);
       fflush(tf);
}