XZ Utils

Spec sheet

Purpose

XZ Utils is a C99 implementation of the .xz file format.Read 8 Oct 2026 · tukaani.org

Intended users

The project describes XZ Embedded as a small .xz decompressor developed with the Linux kernel in mind and usable in other projects.Read 8 Oct 2026 · tukaani.org

Platforms

The supported-platform list includes GNU/Linux, macOS, and Windows, among other operating systems.Read 8 Oct 2026 · tukaani.org

Security

The security page reports a buffer overflow affecting XZ Utils 5.8.2 and older, under conditions the project says likely do not occur in real-world applications.Read 8 Oct 2026 · tukaani.org

Support

The project accepts bug reports through GitHub, email, or IRC, and asks that security issues be reported privately by email or through GitHub's vulnerability reporting feature.Read 8 Oct 2026 · tukaani.org

License

Core components from version 5.5.2beta onward use the BSD Zero Clause License (0BSD), while some scripts and build files use other free software licenses.Read 8 Oct 2026 · tukaani.org

Bindings

The project lists bindings for Python, Perl, Haskell, Delphi, and Free Pascal.Read 8 Oct 2026 · tukaani.org

Components

It includes the liblzma compression library, the xz command line tool, the decompression-only xzdec tool, and shell scripts for viewing, searching, and comparing compressed files.Read 8 Oct 2026 · tukaani.org

Compression library

liblzma provides a general-purpose compression API similar to zlib and supports .xz, .lzma, and raw streams.Read 8 Oct 2026 · tukaani.org

Current release

The site lists XZ Utils 5.8.3, released 2026-03-31, and says it fixes a minor security issue affecting all stable releases.Read 8 Oct 2026 · tukaani.org

File format

The .xz format supports streaming, limited random access, chained filters, integrity checks, concatenation, and padding; it does not provide archiving capabilities.Read 8 Oct 2026 · tukaani.org

Format features

The .xz format supports streaming, limited random-access reading, filter chaining, integrity checks, concatenation, and padding.Read 8 Oct 2026 · tukaani.org

Format limitation

The .xz format is a container for compressed streams and has no archiving capability; each stream holds a single file.Read 8 Oct 2026 · tukaani.org

Licensing

Since version 5.5.2beta, core components use the BSD Zero Clause License; some other parts use licenses including LGPLv2.1, GPLv2, or GPLv3.Read 8 Oct 2026 · tukaani.org

Maintenance

The v5.8 stable branch is maintained; v5.6, v5.4, and v5.2 receive critical fixes only, and v5.0 is unmaintained.Read 8 Oct 2026 · tukaani.org

Security incident

The site reports that XZ Utils 5.6.0 and 5.6.1 release tarballs contained a backdoor inserted by a malicious co-maintainer, disclosed on 2024-03-29 as CVE-2024-3094.Read 8 Oct 2026 · tukaani.org

Security reporting

The project asks people to report security issues privately by email, encrypted if possible, or through GitHub's vulnerability reporting feature.Read 8 Oct 2026 · tukaani.org

Supported formats

The tools support the .xz format and the legacy .lzma format.Read 8 Oct 2026 · github.com

Supported platforms

The project lists GNU/Linux, macOS, Windows, and numerous other operating systems as supported platforms.Read 8 Oct 2026 · tukaani.org

Windows binaries

The site offers XZ Utils 5.8.3 Windows binaries and says they should work on Windows 10 and later; future binary releases are uncertain.Read 8 Oct 2026 · tukaani.org

Windows downloads

The site offers Windows 5.8.3 binaries and says they should work on Windows 10 and later; it says future binary releases are uncertain.Read 8 Oct 2026 · tukaani.org

Where Specifiction places it

• File Compression Software#29 of 366.9