Update release notes wrt #640

Author: cowtowncoder

release-notes/CREDITS-2.x

@@ -386,6 +386,9 @@ Manuel Sugawara (@sugmanue)
   (2.19.0)
  * Contributed fix for #616: CBOR text gets truncated on decoding
   (2.19.3)
+ * Conribued fix for #640: (cbor) CBOR throws ArrayIndexOutOfBoundsException
+   with long ASCII text
+  (2.20.2)
 
 Josh Curry (@seadbrane)
  * Reported, contributed fix for #571: Unable to deserialize a pojo with IonStruct

release-notes/VERSION-2.x

@@ -18,6 +18,13 @@ Active maintainers:
 
 No changes since 2.19
 
+-----
+
+Not yet released
+
+#640: (cbor) CBOR throws ArrayIndexOutOfBoundsException with long ASCII text
+ (reported, fix contributed by Manuel S)
+
 2.19.4 (29-Oct-2025)
 2.19.3 (29-Oct-2025)