Update changelog entry
diff --git a/ChangeLog b/ChangeLog
index f835e4a..64361be 100644
--- a/ChangeLog
+++ b/ChangeLog
@@ -3,8 +3,8 @@
 = mbed TLS x.x.x branch released xxxx-xx-xx
 
 Bugfix
-   * Fix a heap-buffer-overflow during private key parsing. Found through
-     fuzzing.
+   * Fix a 1-byte heap buffer overflow (read-only) during private key parsing.
+     Found through fuzz testing.
 
 = mbed TLS 2.7.0 branch released 2018-02-03