Fix CVE number in ChangeLog
diff --git a/ChangeLog b/ChangeLog
index 7cbbb3f..4ae1a36 100644
--- a/ChangeLog
+++ b/ChangeLog
@@ -3,7 +3,7 @@
 = mbed TLS 2.1.2 released 2015-10-xx
 
 Security
-   * Added fix for CVE-2015-xxxxx to prevent heap corruption due to buffer
+   * Added fix for CVE-2015-5291 to prevent heap corruption due to buffer
      overflow of the hostname or session ticket. Found by Guido Vranken,
      Intelworks.
    * Fix potential double-free if mbedtls_ssl_set_hs_psk() is called more than