In Roundcube Webmail 1.6.x between 1.6.14 and 1.6.16 and 1.7.x before 1.7.1, remote image blocking was not honored for URLs pointing to local/private destinations, which may lead to information disclosure or privilege escalation via a text/html email message.
Exploitability
AV:NAC:LPR:NUI:NScope
S:UImpact
C:LI:LA:N6.5/CVSS:3.1/AV:N/AC:L/PR:N/UI:N/S:U/C:L/I:L/A:NOther