When trying to parse https://github.com/JabRef/jabref/blob/v5.11/CHANGELOG.md, version is always null. I think, it could be because of the used en dash. There is an issue, because the official format might permit en dash (see olivierlacan/keep-a-changelog#497; linked from nbbrd/heylogs#140 (comment)).

    {
      "version": null,
      "link": "https://github.com/JabRef/jabref/compare/v5.10...v5.11",
      "date": null,

If en dash support is "difficult" to implement, maybe this tool coud parse the github compare link to get the version out of that link?

(General background: I was recommended clparse at NiclasvanEyk/keepac#20 (comment))