Atlassian Update – 01 February 2021   Hi, We’ve analyzed this issue and released a fix for it in Jira 8.7 and later, including the Jira 8.13 LTS release. The risk of exploiting this vulnerability is low, as it can only be exploited by someone with admin credentials. We’re not planning to backport the fix to Jira 8.5 LTS, as it might break your current field descriptions that contain HTML, which we don’t want to do in a bugfix release. You can, however, implement the same fix manually by changing one of the Jira settings. To fix this manually, In Jira, go to Administration > General Configuration , and select Edit Settings . Set the Enable HTML in field descriptions and list values setting to OFF. After disabling this setting, you will also need to update the field descriptions that contain HTML, and remove the markup. This is the breaking behavior we’ve mentioned above. We also advise to upgrade to the latest Jira 8.13 LTS release.   Thank you, Jira Server and Data Center Team