What’s Vulnerable › Vulnerabilities

CVE-2026-54616: NanaZip: Heap out-of-bounds read in NanaZip SquashFS LZ4 decompressor via unchecked negative return value

• Severity: high (CVSS 7.1 v3.1)
• Exploited in the wild: not listed in CISA KEV
• EPSS: 0.4% probability of exploitation in the next 30 days
• Public exploit or detection template: none known
• Published: 2026-08-20 · updated 2026-10-18
• Weakness: CWE-125

Description

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.

Affected products

• M2Team NanaZip: from 1.0.88.0, < 6.0.1698.0; from 6.5.1638.0, < 6.5.1742.0

References

• https://github.com/M2Team/NanaZip/commit/733e8570d2ba96c3e52aab44f5fd886775d5952f
• https://github.com/M2Team/NanaZip/commit/ce0322a1932e16a53e4a13e48bc61804c7826956
• https://github.com/M2Team/NanaZip/releases/tag/6.0.1698.0
• https://github.com/M2Team/NanaZip/releases/tag/6.5.1742.0
• https://github.com/M2Team/NanaZip/security/advisories/GHSA-95x5-qvvm-hmfp
• https://github.com/M2Team/NanaZip/security/advisories/GHSA-95x5-qvvm-hmfp

Get alerted when CVE-2026-54616 or the next vulnerability affects your stack