Atom feedMKVToolNix v103.0 released
2026-10-18 — mosu
Hey yall!
Here’s another release, again nohing major. But there was one particular bug fix for the MP4 reader that fixes a potential loss of frames at the end of the end under certain, not too rare circumstances. Therefore I suggest everyone update.
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 103.0 “The Darkness” 2026-10-18
New features and enhancements
- mkvmerge: AVC/H.264: the stereo mode is now set from the frame packing arrangement SEI message in the video stream if neither the command line nor the container specifies one. This works for MP4, Matroska, AVC elementary stream and MPEG transport stream input and is already known during file identification. Implements the AVC part of #6309.
- mkvmerge: HEVC/H.265: the stereo mode is now set from the frame packing arrangement SEI message in the video stream if neither the command line nor the container specifies one. This works for MP4, Matroska, HEVC elementary stream and MPEG transport stream input and is already known during file identification. Implements the HEVC part of #6309.
- MKVToolNix GUI: multiplexer: added new actions to the tracks context menu for enabling/disabling all items belonging to the same source file as the selected item. Implements #6318.
Bug fixes
- mkvmerge: MP4 reader: fixed losing video frames at the end of the file due to flushing the packetizers too early (when the first track ends instead of only when all tracks in the file have ended). Another byproduct is that
BlockDurationattributes aren’t set for the last frame when they aren’t needed anymore. Fixes #6320. - MKVToolNix GUI: multiplexer: when identification fails due to an unrecognized or unsupported format, clicking the “Cancel” button in the error dialog shown no longer locks up the GUI in the state of “identification is still running”, which disabled most elements. Fixes #6298.
- MKVToolNix GUI: chapter editor: when adding chapters mandatory elements set to their default values are removed in the underlying data structures. This restores consistency to how the chapter editor worked when copying values from the UI into them for the selected chapter. The result is that those elements won’t show up in saved XML/Matroska files even if they have never been selected in the UI. Fixes #6294.
- macOS: GUI: fixed check boxes in lists such as the multiplexer’s track list being invisible on macOS 27 by patching the Qt bundled with the app. Patch by corticalcode, based on the fix J.D. Purcell proposed in QTBUG-150017. Fixes #6307.
Have fun 😁
MKVToolNix v102.0 released
2026-09-14 — mosu
Hello gentle people!
An unsually short time between releases means a security fix, and that’s almost all this release is.
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 102.0 “Little Houses” 2026-09-14
Bug fixes
- MKVToolNix GUI: executing actions, type “execute a program”: all the variables (
<MTX_…>) will now be replaced again in the argument list to the program to be executed. This was broken in v100. Fixes #6306.
Security fixes
- CVE-2026-90783: avilib: fixed potential heap overflows/invalid memory access in the ODML index handling due to unsiged integer multiplication wrapping around (colloquially known as “overflowing”) with specifically crafted AVI files. Affects only mkvmerge as the other tools do not read AVIs. Reported by Tristan Madani TristanInSec@gmail.com.
Have fun! 😁
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
.icoones 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.xmlwas renamed toorg.bunkus.mkvtoolnix-gui.metainfo.xml.
Have fun! 💝😁
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