Version 5.23.0, which just hit NPM, is the 100th release on CodeMirror github repository since 2.0 in March 2011. It has 34 new commits and you can also download it as a zip file.
Release notes
Bug fixes
Presentation-related elements DOM elements are now marked as such to help screen readers.
markdown mode: Be more picky about what HTML tags look like to avoid false positives.
New features
findModeByMIME now understands +json and +xml MIME suffixes.
closebrackets addon: Add support for an override option to ignore language-specific defaults.
panel addon: Add a stable option that auto-scrolls the content to keep it in the same place when inserting/removing a panel.