added security tags
diff --git a/ChangeLog b/ChangeLog
index cdd8ad0..4a4d4b2 100644
--- a/ChangeLog
+++ b/ChangeLog
@@ -6,7 +6,9 @@
     * Added SAE J2735 example.
     * CVE-2017-12966 verified not present.
     * Fix incomplete (failed) CHOICE XER decoding memory leak.
+      (Severity: medium; Security impact: medium)
     * Fix REAL type overwrite conversion memory leak.
+      (Severity: low; Security impact: medium)
 
 0.9.28: 2017-03-26
     * PER decoding: avoid memory leak on error. By github.com/simo5