The keyword refers to the source code archive of zlib version 1.2.13 , compressed using the tar.xz format. Released on October 13, 2022, version 1.2.13 was a critical update for the widely-used data compression library. What is zlib?

The extension indicates a two-step archival and compression process: Releases · madler/zlib - GitHub

The 1.2.13 release was primarily a security and bug-fix update. Notable changes included:

Zlib is a free, patent-free, lossless data compression library used by nearly every major operating system, including . It implements the Deflate algorithm, which is the same technology behind the ZIP and GZIP formats. It is essential for:

: Addressed CVE-2022-37434 , a bug in the inflateGetHeader() function that could lead to vulnerabilities.

: Core component of Linux, iOS, and Android.