M2Team NanaZip prior 6.0.1698.0/6.5.1742.0 SquashFS SquashfsHandler.cpp Lz4Decode heap-based overflow

Summaryinfo

A vulnerability has been found in M2Team NanaZip and classified as critical. This vulnerability affects the function Lz4Decode of the file NanaZip.Core/SevenZip/CPP/7zip/Archive/SquashfsHandler.cpp of the component SquashFS Handler. This manipulation causes heap-based overflow. This vulnerability is handled as CVE-2026-54616. The attack can be initiated remotely. There is not any exploit available.

Detailsinfo

A vulnerability has been found in M2Team NanaZip and classified as critical. Affected by this vulnerability is the function Lz4Decode of the file NanaZip.Core/SevenZip/CPP/7zip/Archive/SquashfsHandler.cpp of the component SquashFS Handler. The manipulation with an unknown input leads to a heap-based overflow vulnerability. The CWE definition for the vulnerability is CWE-122. A heap overflow condition is a buffer overflow, where the buffer that can be overwritten is allocated in the heap portion of memory, generally meaning that the buffer was allocated using a routine such as malloc(). As an impact it is known to affect confidentiality, integrity, and availability. The summary by CVE is:

NanaZip is the 7-Zip derivative intended for the modern Windows experience. From version 1.0.88.0 until stable version 6.0.1698.0 and preview version 6.5.1742.0, the Lz4Decode function in NanaZip.Core/SevenZip/CPP/7zip/Archive/SquashfsHandler.cpp rejects only a zero return from LZ4_decompress_safe even though malformed input produces a negative error value. The negative int is converted to the unsigned SizeT destLen and then truncated into outBufWasWrittenSize, causing ReadBlock to trust an attacker-inflated _cachedUnpackBlockSize. During fragment extraction, an attacker-controlled inode Offset can make memcpy read beyond the _cachedBlock heap allocation and place adjacent heap contents in the extracted file, or crash the process. This issue is fixed in stable version 6.0.1698.0 and preview version 6.5.1742.0.

The advisory is shared at github.com. This vulnerability is known as CVE-2026-54616 since 06/15/2026. The exploitation appears to be easy. The attack can be launched remotely. The exploitation doesn't need any form of authentication. It demands that the victim is doing some kind of user interaction. Technical details are known, but no exploit is available.

Upgrading to version 6.0.1698.0 or 6.5.1742.0 eliminates this vulnerability.

If you want to get the best quality for vulnerability data then you always have to consider VulDB.

Productinfo

Vendor

• M2Team

Name

• NanaZip

Website

• Product: https://github.com/M2Team/NanaZip/

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