Merge pull request #3770 from ActiveState/mitchell/0-48-1-changelog

Updated changelog for 0.48.1.

Author: mitchell-as

changelog.md

@@ -6,6 +6,12 @@ The format is based on [Keep a Changelog](https://keepachangelog.com/en/1.0.0/),
 and this project adheres to
 [Semantic Versioning](https://semver.org/spec/v2.0.0.html).
 
+## 0.48.1
+
+### Security
+
+Addressed all known, fixable CVEs.
+
 ## 0.48.0
 
 ### Added