diff --git a/ChangeLog b/ChangeLog
index 227faed6b..1154075e0 100644
--- a/ChangeLog
+++ b/ChangeLog
@@ -1,5 +1,17 @@
 mbed TLS ChangeLog (Sorted per branch, date)
 
+= mbed TLS x.x.x branch released xxxx-xx-xx
+
+Security
+   * Fix a potential heap buffer overflow in mbedtls_ssl_write. When the (by
+     default enabled) maximum fragment length extension is disabled in the
+     config and the application data buffer passed to mbedtls_ssl_write
+     is larger than the internal message buffer (16384 bytes by default), the
+     latter overflows. The exploitability of this issue depends on whether the
+     application layer can be forced into sending such large packets. The issue
+     was independently reported by Tim Nordell via e-mail and by Florin Petriuc
+     and sjorsdewit on GitHub. Fix proposed by Florin Petriuc in #1022. Fixes #707.
+
 = mbed TLS 2.6.0 branch released 2017-08-10
 
 Security