CVE-2026-54616

HIGHCVSS 7.1/10EPSS 0.32%

Last modified

CVE-2026-54616 is a high-severity vulnerability rated 7.1/10 on the CVSS scale. 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. EPSS estimates a 0.32% chance of exploitation in the next 30 days.

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.

Metrics

EPSS Probability
0.32%

24.9th percentile

Probability of exploitation in the next 30 days. Learn more

Weakness Enumeration

Affected Software

Source: CNA advisory (CVE.org). NVD analysis pending.

VendorProductVersions
M2TeamNanaZip>= 1.0.88.0, < 6.0.1698.0; >= 6.5.1638.0, < 6.5.1742.0

References

Timeline

Published
Last Modified
Status
Deferred

Frequently Asked Questions

What is CVE-2026-54616?
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.
How severe is CVE-2026-54616?
CVE-2026-54616 has a CVSS score of 7.1/10 (HIGH severity). The EPSS model estimates a 0.32% probability of exploitation in the next 30 days.
How do I fix CVE-2026-54616?
Check the vendor references and advisories linked above for patched versions and mitigation guidance. You can also run a Strix scan to test if your systems are affected.

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Source: NVD / NIST