Add changelog entry
diff --git a/ChangeLog b/ChangeLog
index 2a993b9..0dac497 100644
--- a/ChangeLog
+++ b/ChangeLog
@@ -2,6 +2,13 @@
 
 = mbed TLS 2.7.X branch released XXXX-XX-XX
 
+Security
+   * To avoid a side channel vulnerability when parsing an RSA private key,
+     read all the CRT parameters from the DER structure rather than
+     reconstructing them. Found by Alejandro Cabrera Aldaya and Billy Bob
+     Brumley. Reported and fix contributed by Jack Lloyd.
+     ARMmbed/mbed-crypto#352
+
 Bugfix
    * Allow loading symlinked certificates. Fixes #3005. Reported and fixed
      by Jonathan Bennett <JBennett@incomsystems.biz> via #3008.