Apply by doing:
       cd /usr/src
       patch -p0 < 001_httpd.patch

And then rebuild and install httpd and its modules:
       cd usr.sbin/httpd
       make -f Makefile.bsd-wrapper obj
       make -f Makefile.bsd-wrapper cleandir
       make -f Makefile.bsd-wrapper depend
       make -f Makefile.bsd-wrapper
       make -f Makefile.bsd-wrapper install

If httpd had been started, you might want to run
       apachectl stop
before running "make install", and
       apachectl start
afterwards.

Index: usr.sbin/httpd/src/main//http_protocol.c
===================================================================
RCS file: /cvs/src/usr.sbin/httpd/src/main/http_protocol.c,v
retrieving revision 1.30
retrieving revision 1.30.4.1
diff -u -p -r1.30 -r1.30.4.1
--- usr.sbin/httpd/src/main//http_protocol.c    11 Feb 2006 19:15:57 -0000      1.30
+++ usr.sbin/httpd/src/main//http_protocol.c    1 Nov 2006 21:18:38 -0000       1.30.4.1
@@ -2922,7 +2922,8 @@ API_EXPORT(void) ap_send_error_response(
           ap_rvputs(r, "The expectation given in the Expect request-header"
                     "\nfield could not be met by this server.<P>\n"
                     "The client sent<PRE>\n    Expect: ",
-                     ap_table_get(r->headers_in, "Expect"), "\n</PRE>\n"
+                     ap_escape_html(r->pool, ap_table_get(r->headers_in,
+                     "Expect")), "\n</PRE>\n"
                     "but we only allow the 100-continue expectation.\n",
                     NULL);
           break;