Global Buffer Overflow in GNU Gzip LZH Decompression

CVE-2026-41992

What is CVE-2026-41992?

GNU gzip suffers from a global buffer overflow vulnerability in its LZH decompression logic. This vulnerability arises due to the improper reuse of a shared global state across different decompression formats within a single execution instance. Specifically, when decompressing a specially crafted LZW file followed by a carefully constructed LZH file using a single 'gzip -d' command, an attacker can manipulate the shared global state, triggering an out-of-bounds read during the LZH decompression process. This flaw results from the LZH logic utilizing stale values retained in the global array, which can lead to undesirable behavior and potential data leakage.

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