MKVToolNix v101 released

2026-08-24 — mosu

Hey y’all!

The first release after the milestone round version v100 is here, v101. It’s pretty small, but I still suggest everyone update due to the inclusion of updated underlying libraries libEBML & libMatroska. Both are updated to their respective releases from a couple of weeks ago which fix several potential invalid memory access cases that could be triggered by reading files broken in very rare, specific ways. Basically they’re potentially security-relevant.

You can download the source code or one of the packages. The Windows packages as well as the Linux AppImage are available already. The other Linux packages & the macOS disk image are still being built and will be available over the course of the next couple of hours.

Here are the NEWS since the previous release:

Version 101.0 “Time To Turn” 2026-08-24

New features and enhancements

• translations: substantial extension of the Czech translation by Michal Várady.

Bug fixes

• mkvmerge: TrueHD parser: fixed mkvmerge dropping the last TrueHD frame if its size was smaller than 12 bytes. Fixes #6296.
• MKVToolNix GUI: job runner: the variable <MTX_INSTALLATION_DIRECTORY> will be replaed in the executable position of the command-line for the program to execute again. Fixes #6299.
• Windows: fixed converting the scalable SVG icons into the bitmap .ico ones used on Windows so that the grey background remains uniform & doesn’t get garbled. Fixes #6280.

Build system changes

• The bundled libraries libEBML & libMatroska were updated to v1.4.7 & v1.7.2 respectively. Those versions fix various possible invalid memory accesses when reading data broken in certain, very specific ways, making them security sensitive.
• libEBML v1.4.7 & libMatroska v1.7.2 are now required.
• The meta info file org.bunkus.mkvtoolnix-gui.appdata.xml was renamed to org.bunkus.mkvtoolnix-gui.metainfo.xml.

Have fun! 💝😁