Heap out-of-bounds read via negative LZ4 return
Published Aug 20, 2026 · Updated Aug 20, 2026
Out-of-bounds read in NanaZip before 6.0.1698.0 and 6.5.1742.0 allows remote attackers to read heap data or crash NanaZip with a crafted SquashFS archive. In SquashfsHandler.cpp, Lz4Decode rejects only a zero return from LZ4_decompress_safe; a negative error value is cast to SizeT, which inflates the cached unpacked-block length that ReadBlock later trusts during fragment extraction. Exploitation requires a user to open or extract an attacker-supplied archive, after which a controlled inode offset can drive memcpy past the heap buffer and copy adjacent heap bytes into the output file or terminate the process.
Summary
What happened
Out-of-bounds read in NanaZip before 6.0.1698.0 and 6.5.1742.0 allows remote attackers to read heap data or crash NanaZip with a crafted SquashFS archive. In SquashfsHandler.cpp, Lz4Decode rejects only a zero return from LZ4_decompress_safe; a negative error value is cast to SizeT, which inflates the cached unpacked-block length that ReadBlock later trusts during fragment extraction. Exploitation requires a user to open or extract an attacker-supplied archive, after which a controlled inode offset can drive memcpy past the heap buffer and copy adjacent heap bytes into the output file or terminate the process.
The record
- CVE
- CVE-2026-54616
- Published
- Aug 20, 2026
- Updated
- Aug 20, 2026
- Vendor
- M2-Team
- Product
- NanaZip
- Classifications
- CWE-125, T1203
- Attack vector
- network
- Privileges
- unauthenticated
Timeline
How it unfolded
- Aug 20, 2026CVE publishedPublication date reported by the CVE source.
- Aug 20, 2026Record updatedLatest update available in the CVE record.
Exploitability
Present is not the same as exploitable
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Is a vulnerable build present?
Compare these published version ranges with your installed build and any vendor patches.
- Affected versionversion=>= 1.0.88.0, < 6.0.1698.0
- Affected versionversion=>= 6.5.1638.0, < 6.5.1742.0
What conditions does exploitation require?
What is affected?
Published CVSS scores
CVSS describes severity. EPSS estimates exploitation probability.
Attacks
What attackers are doing with it
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Public exploit references
No public exploit references are available in this record.
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Technologies
Your stack
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Your stack
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