Update CHANGELOG

Author: motdotla

CHANGELOG.md

@@ -2,13 +2,13 @@
 
 All notable changes to this project will be documented in this file. See [standard-version](https://github.com/conventional-changelog/standard-version) for commit guidelines.
 
-## [Unreleased](https://github.com/dotenv-org/python-dotenv-vault/compare/v0.5.1...master)
+## [Unreleased](https://github.com/dotenv-org/python-dotenv-vault/compare/v0.6.4...master)
 
 ## 0.6.4
 
 ### Changed
 
-- Bump Cryptography above 41.0.3 to resolve [#19](https://github.com/dotenv-org/python-dotenv-vault/issues/19) (High severity [CVE-2023-38325](https://nvd.nist.gov/vuln/detail/CVE-2023-38325))
+- Bump Cryptography above 41.0.3 to resolve [#19](https://github.com/dotenv-org/python-dotenv-vault/issues/19) - high severity [CVE-2023-38325](https://nvd.nist.gov/vuln/detail/CVE-2023-38325)
 
 ## 0.6.3