Add ChangeLog entry
diff --git a/ChangeLog b/ChangeLog
index 1d06476..8f7843d 100644
--- a/ChangeLog
+++ b/ChangeLog
@@ -1,5 +1,11 @@
 mbed TLS ChangeLog (Sorted per branch, date)
 
+= mbed TLS 2.1.x released xxxx-xx-xx
+
+Bugfix
+   * Fix ssl_parse_record_header() to silently discard invalid DTLS records
+     as recommended in RFC 6347 Section 4.1.2.7.
+
 = mbed TLS 2.1.9 branch released 2017-08-10
 
 Security