GNU gzip LZH buffer overflow via global state reuse
CVE-2026-41992 Published on June 29, 2026
Global Buffer Overflow in GNU gzip
GNU gzip contains a global buffer overflow vulnerability in the LZH decompression logic caused by improper reuse of shared global state between different decompression formats within a single execution. GNU gzip maintains a global array that is shared across the LZ77, LZW, and LZH decompression routines and is not reinitialized between files processed in the same invocation.
By decompressing a specially crafted LZW file followed by a specially crafted LZH file in a single gzip -d command, an attacker can poison the shared global state and subsequently trigger an outofbounds read in the LZH decoder. The LZH decompression logic follows stale values left in the shared array, causing reads past the end of the allocated global buffer.
This issue has been fixed in the commit 63dbf6b3b9e6e781df1a6a64e609b10e23969681
Weakness Type
Buffer Over-read
The software reads from a buffer using buffer access mechanisms such as indexes or pointers that reference memory locations after the targeted buffer. This typically occurs when the pointer or its index is incremented to a position beyond the bounds of the buffer or when pointer arithmetic results in a position outside of the valid memory location to name a few. This may result in exposure of sensitive information or possibly a crash.
Products Associated with CVE-2026-41992
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Affected Versions
GNU gzip:- Before and including 1.14 is affected.