A persistent XSS could be injected via a tracker field label.
Impact
An attacker who has the possibility to administrate a tracker could use this vulnerability to force a victim to execute uncontrolled code.
CVSS3 score: 4.1 (CVSS:3.0/AV:N/AC:L/PR:H/UI:N/S:C/C:N/I:L/A:N)
Proof of concept
Edit or create a tracker field and put this payload in the label: onClick=alert(1) a=
Now, go to an artifact in this tracker and edit the field you have edited or created. The XSS is trigerred.
References
https://cwe.mitre.org/data/definitions/79.html
https://www.owasp.org/index.php/Cross-site_Scripting_%28XSS%29