Mumble before 1.3.4 allows remote code execution if a victim navigates to a crafted URL on a server list and clicks on the Open Webpage text.

Qt 5.12.2 through 5.14.2, as used in unofficial builds of Mumble 1.3.0 and other products, mishandles OpenSSL's error queue, which can cause a denial of service to QSslSocket users. Because errors leak in unrelated TLS sessions, an unrelated session may be disconnected when any handshake fails. (Mumble 1.3.1 is not affected, regardless of the Qt version.)

Mumble: murmur-server has DoS due to malformed client query

murmur in Mumble through 1.2.19 before 2018-08-31 mishandles multiple concurrent requests that are persisted in the database, which allows remote attackers to cause a denial of service (daemon hang or crash) via a message flood.

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.

The needSamples method in AudioOutputSpeech.cpp in the client in Mumble 1.2.4 and the 1.2.3 pre-release snapshots, Mumble for iOS 1.1 through 1.2.2, and MumbleKit before commit fd190328a9b24d37382b269a5674b0c0c7a7e36d does not check the return value of the opus_decode_float function, which allows remote attackers to cause a denial of service (crash) and possibly execute arbitrary code via a crafted Opus voice packet, which triggers an error in opus_decode_float, a conversion of a negative integer to an unsigned integer, and a heap-based buffer over-read and over-write.

The opus_packet_get_samples_per_frame function in client in Mumble 1.2.4 and the 1.2.3 pre-release snapshots allows remote attackers to cause a denial of service (crash) via a crafted length prefix value, which triggers a NULL pointer dereference or a heap-based buffer over-read (aka "out-of-bounds array access").

The (1) opus_packet_get_nb_frames and (2) opus_packet_get_samples_per_frame functions in the client in MumbleKit before commit fd190328a9b24d37382b269a5674b0c0c7a7e36d and Mumble for iOS 1.1 through 1.2.2 do not properly check the return value of the copyDataBlock method, which allow remote attackers to cause a denial of service (NULL pointer dereference and crash) via a crafted length prefix value in an Opus voice packet.

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.