CVE-2026-34743

Description

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.

References

• https://github.com/tukaani-project/xz/commit/c8c22869e780ff57c96b46939c3d79ff99395f87
• https://github.com/tukaani-project/xz/releases/tag/v5.8.3
• https://github.com/tukaani-project/xz/security/advisories/GHSA-x872-m794-cxhv
• http://www.openwall.com/lists/oss-security/2026/03/31/13