The client in Mumble 1.2.x before 1.2.6 allows remote attackers to force the loading of an external file and cause a denial of service (hang and resource consumption) via a crafted string that is treated as rich-text by a Qt widget, as demonstrated by the (1) user or (2) channel name in a Qt dialog, (3) subject common name or (4) email address to the Certificate Wizard, or (5) server name in a tooltip.

The QSvg module in Qt, as used in the Mumble client 1.2.x before 1.2.6, allows remote attackers to cause a denial of service (hang and resource consumption) via a local file reference in an (1) image tag or (2) XML stylesheet in an SVG file.

Mumble 1.2.3 and earlier uses world-readable permissions for .local/share/data/Mumble/.mumble.sqlite files in home directories, which might allow local users to obtain a cleartext password and configuration data by reading a file.