$re = '/^## (\d+\.?){3}.+?(?=## \d)/s';
$str = '## 8.6.0
- **Upload date:** November 19, 2020
- **Release date:** TBC
- **Internal version:** 1171
### Feature
- dsfdsfds
- sdfdsf
- dsfdsf
### Bug fixes
- sdfsaf
- sdfsad
- sdfsdfdsf
### Internal
- sadfsdfsda
- fsdfgsadfasd
- sdfsda
## 8.5.1
- **Upload date:** November 09, 2020
- **Release date:** November 12, 2020
- **Internal version:** 1170';
preg_match_all($re, $str, $matches, PREG_SET_ORDER, 0);
// Print the entire match result
var_dump($matches);
Please keep in mind that these code samples are automatically generated and are not guaranteed to work. If you find any syntax errors, feel free to submit a bug report. For a full regex reference for PHP, please visit: http://php.net/manual/en/ref.pcre.php