diff --git a/ext/session/session.c b/ext/session/session.c
index 74a7f4a1da70b..3cdb6606626bb 100644
--- a/ext/session/session.c
+++ b/ext/session/session.c
@@ -1228,7 +1228,7 @@ static void php_session_remove_cookie(TSRMLS_D) {
 
 static void php_session_send_cookie(TSRMLS_D) /* {{{ */
 {
-	smart_str ncookie = {0};
+	smart_str ncookie = {0}, dcookie = {0};
 	char *date_fmt = NULL;
 	char *e_session_name, *e_id;
 
@@ -1244,6 +1244,39 @@ static void php_session_send_cookie(TSRMLS_D) /* {{{ */
 		return;
 	}
 
+	/* Try to remove offensive cookie to prevent DoS */
+	e_session_name = php_url_encode(PS(session_name), strlen(PS(session_name)), NULL);
+	smart_str_appends(&dcookie, COOKIE_SET_COOKIE);
+	smart_str_appends(&dcookie, e_session_name);
+	smart_str_appends(&dcookie, "[]=");
+	date_fmt = php_format_date("D, d-M-Y H:i:s T", sizeof("D, d-M-Y H:i:s T")-1, 1, 0 TSRMLS_CC);
+	smart_str_appends(&dcookie, COOKIE_EXPIRES);
+	smart_str_appends(&dcookie, date_fmt);
+	efree(date_fmt);
+
+
+	if (PS(cookie_path)[0]) {
+		smart_str_appends(&dcookie, COOKIE_PATH);
+		smart_str_appends(&dcookie, PS(cookie_path));
+	}
+
+	if (PS(cookie_domain)[0]) {
+		smart_str_appends(&dcookie, COOKIE_DOMAIN);
+		smart_str_appends(&dcookie, PS(cookie_domain));
+	}
+
+	if (PS(cookie_secure)) {
+		smart_str_appends(&dcookie, COOKIE_SECURE);
+	}
+
+	if (PS(cookie_httponly)) {
+		smart_str_appends(&dcookie, COOKIE_HTTPONLY);
+	}
+
+	smart_str_0(&dcookie);
+	efree(e_session_name);
+	sapi_add_header_ex(dcookie.c, dcookie.len, 0, 0 TSRMLS_CC);
+
 	/* URL encode session_name and id because they might be user supplied */
 	e_session_name = php_url_encode(PS(session_name), strlen(PS(session_name)), NULL);
 	e_id = php_url_encode(PS(id), strlen(PS(id)), NULL);
@@ -1327,9 +1360,16 @@ PHPAPI const ps_serializer *_php_find_ps_serializer(char *name TSRMLS_DC) /* {{{
 }
 /* }}} */
 
-#define PPID2SID \
-		convert_to_string((*ppid)); \
-		PS(id) = estrndup(Z_STRVAL_PP(ppid), Z_STRLEN_PP(ppid))
+static void ppid2sid(zval **ppid TSRMLS_DC) {
+	if (Z_TYPE_PP(ppid) != IS_STRING) {
+		PS(id) = NULL;
+		PS(send_cookie) = 1;
+	} else {
+		convert_to_string((*ppid));
+		PS(id) = estrndup(Z_STRVAL_PP(ppid), Z_STRLEN_PP(ppid));
+		PS(send_cookie) = 0;
+	}
+}
 
 static void php_session_reset_id(TSRMLS_D) /* {{{ */
 {
@@ -1418,9 +1458,8 @@ PHPAPI void php_session_start(TSRMLS_D) /* {{{ */
 				Z_TYPE_PP(data) == IS_ARRAY &&
 				zend_hash_find(Z_ARRVAL_PP(data), PS(session_name), lensess + 1, (void **) &ppid) == SUCCESS
 		) {
-			PPID2SID;
+			ppid2sid(ppid TSRMLS_CC);
 			PS(apply_trans_sid) = 0;
-			PS(send_cookie) = 0;
 			PS(define_sid) = 0;
 		}
 
@@ -1429,8 +1468,7 @@ PHPAPI void php_session_start(TSRMLS_D) /* {{{ */
 				Z_TYPE_PP(data) == IS_ARRAY &&
 				zend_hash_find(Z_ARRVAL_PP(data), PS(session_name), lensess + 1, (void **) &ppid) == SUCCESS
 		) {
-			PPID2SID;
-			PS(send_cookie) = 0;
+			ppid2sid(ppid TSRMLS_CC);
 		}
 
 		if (!PS(use_only_cookies) && !PS(id) &&
@@ -1438,8 +1476,7 @@ PHPAPI void php_session_start(TSRMLS_D) /* {{{ */
 				Z_TYPE_PP(data) == IS_ARRAY &&
 				zend_hash_find(Z_ARRVAL_PP(data), PS(session_name), lensess + 1, (void **) &ppid) == SUCCESS
 		) {
-			PPID2SID;
-			PS(send_cookie) = 0;
+			ppid2sid(ppid TSRMLS_CC);
 		}
 	}
 
diff --git a/ext/session/tests/bug66827.phpt b/ext/session/tests/bug66827.phpt
new file mode 100644
index 0000000000000..4e1a4f7aea693
--- /dev/null
+++ b/ext/session/tests/bug66827.phpt
@@ -0,0 +1,12 @@
+--TEST--
+Bug #66827: Session raises E_NOTICE when session name variable is array.
+--INI--
+--SKIPIF--
+<?php include('skipif.inc'); ?>
+--FILE--
+<?php
+$_COOKIE[session_name()] = array();
+session_start();
+echo 'OK';
+--EXPECTF--
+OK