In the "Logging Details" report, some parameters were not being properly sanitised.
CiviCRM Versions 5.10.2 and earlier
CiviCRM Versions 5.10.3 and 4.7.4
Upgrae to the lastest version of CiviCRM.
Patrick Figel of Greenpeace for reporting the issue.
Seamus Lee of Australian Greens for fixing the issue.