GHSA-477V-W82M-634J Shoutrrr util package DoS via sending 2000, 4000, or 6000 character messages

The package github.com/containrrr/shoutrrr/pkg/util before 0.6.0 are vulnerable to Denial of Service DoS via the util.PartitionMessage function. Exploiting this vulnerability is possible by sending exactly 2000, 4000, or 6000 characters messages...