Add ChangeLog entry for undefined behavior fix in test_suite_nist_kw
diff --git a/ChangeLog b/ChangeLog
index 01da443..4cfee37 100644
--- a/ChangeLog
+++ b/ChangeLog
@@ -13,6 +13,7 @@
    * Enable Suite B with subset of ECP curves. Make sure the code compiles even
      if some curves are not defined. Fixes #1591 reported by dbedev.
    * Fix misuse of signed arithmetic in the HAVEGE module. #2598
+   * Fix undefined memset(NULL) call in test_suite_nist_kw.
 
 Changes
    * Make it easier to define MBEDTLS_PARAM_FAILED as assert (which config.h