After updating my Jira to version 7.4.0, most of my graphs and diagrams on dashboard started showing garbled text on labels and captions. Every other text was okay.
This is most probably due to the missing fonts in your Linux installation.
This article on Attlassian site has the answer for Confluence which also applies to Jira. My Linux is already patched with the latest official updates.
OS: Centos 7.4.1708
Jira Server: v7.4.0
To fix it you need to install the missing fonts.
sudo yum install ghostscript \ dejavu-fonts-common \ dejavu-sans-fonts \ dejavu-sans-mono-fonts \ motif
In order for Jira to pick up the changes, apply the below steps:
sudo systemctl stop jira
Rebuild the font cache by using the following command:
sudo fc-cache -s
sudo systemctl start jira
Clear your browser cache and verify Jira is presenting the text properly.