CVE-2026-34743

XZ Utils provide a general-purpose data-compression library plus command-line tools. Prior to version 5.8.3, 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. This issue has been patched in version 5.8.3.

• xz-utils 5.8.3-1 (bug https://bugs.debian.org/cgi-bin/bugreport.cgi?bug=1132497) [trixie] - xz-utils 5.8.1-1+deb13u1 [bookworm] - xz-utils 5.4.1-1+deb12u1 https://tukaani.org/xz/index-append-overflow.html Fixed by: https://github.com/tukaani-project/xz/commit/c8c22869e780ff57c96b46939c3d79ff99395f87 (v5.8.3)