KMail since version 5.3.0 used a QWebEngine based viewer that had JavaScript enabled. Since the generated html is executed in the local file security context by default access to remote and local URLs was enabled.
2016-12-23T22:59:00.267
2025-04-12T10:46:40.837
Deferred
CVSSv3.0: 8.1 (HIGH)
AV:N/AC:M/Au:N/C:P/I:P/A:N
8.6
4.9