xz-5.8.3

[Joe Locash]

IMPORTANT: This includes a fix for CVE-2026-34743 which affects all XZ Utils versions since
            5.0.0. No new 5.2.x, 5.4.x, or 5.6.x releases will be made, but the fix is in 
            the v5.2, v5.4, and v5.6 branches in the xz Git repository.

5.8.3 (2026-03-31)

    * liblzma:

        - Fix a buffer overflow in lzma_index_append(): If
          lzma_index_decoder() was used to decode an Index that
          contained no Records, the resulting lzma_index was left in
          a state where where a subsequent lzma_index_append() would
          allocate too little memory, and a buffer overflow would occur.

          The lzma_index functions are rarely used by applications
          directly. In the few applications that do use these functions,
          the combination of function calls required to trigger this bug
          are unlikely to exist, because there typically is no reason to
          append Records to a decoded lzma_index. Thus, it's likely that
          this bug cannot be triggered in any real-world application.

          The bug was reported and discovered by Cantina using their
          AppSec agent, Apex.

        - Fix the build on Windows ARM64EC.

        - Add "License: 0BSD" to liblzma.pc.

    * xz:

        - Fix invalid memory access in --files and --files0. All of
          the following must be true to trigger it:

            1. A string being read (which supposedly is a filename) is
               at least SIZE_MAX / 2 bytes long. This size is plausible
               on 32-bit platforms (2 GiB - 1 B).

            2. realloc(ptr, SIZE_MAX / 2 + 1) must succeed.
               On glibc >= 2.30 it shouldn't because the value
               exceeds PTRDIFF_MAX.

            3. An integer overflow results in a realloc(ptr, 0) call.
               If it doesn't return NULL, then invalid memory access
               will occur.

        - On QNX, don't use fsync() on directories because it fails.

    * Autotools: Enable 32-bit x86 assembler on Hurd by default.
      It was already enabled in the CMake-based build.

    * Translations: Add Arabic man page translations.

[Bruce Dubbs]

I see that this is rated as 5.2 MEDIUM.