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

Unknown severity · Source severity not reportedCVE-2026-54616

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

Answer in brief

CVE-2026-54616 records a Unknown severity vulnerability in NanaZip: Heap out-of-bounds read in NanaZip SquashFS LZ4 decompressor via unchecked negative return value. The current sources do not mark it as known exploited. The current feed maps M2Team/NanaZip (generic). Check affected ranges and fixed versions before updating.

Analysis pending evidence review

HOL Guard separates source facts from reviewed analysis. See the methodology.

Published Aug 20, 2026Updated Aug 20, 2026Source checked Aug 20, 2026First seen by HOL Aug 20, 2026Material review Aug 20, 2026

Upstream Advisory

Key facts

Risk: Unknown severitySource severity not reported
Exploitation: Not marked as known exploited
Affected software: 1 mapped package or product
Fix availability: Not reported

Why this deserves its current priority

A CVSS score is not reported in the current record. The current sources do not mark it as known exploited. Treat this as a source-backed prioritization signal, not a statement about your environment.

Analysis status

Analysis pending evidence review

Factual feed record only; HOL analysis is not approved for indexing. Read the methodology.

Affected scope and exposure questions

The current feed maps M2Team/NanaZip (generic). Check affected ranges and fixed versions before updating.

Mapped affected packages and fixed versions
Package	Affected range	Fixed version
M2Team/NanaZipgeneric	>= 1.0.88.0, < 6.0.1698.0 \|\| >= 6.5.1638.0, < 6.5.1742.0	Not reported

Recommended response

Check inventory. Check lockfiles and deployed manifests for M2Team/NanaZip.
Review the reported fix. Monitor this advisory for an available fix and review any installs of the affected package.

Evidence timeline and material changes

Published upstream
Aug 20, 2026
Evidence: source:cvelist:source_dates:source-dates:record
Source modified
Aug 20, 2026
Evidence: source:cvelist:source_dates:source-dates:record
First seen by HOL
Aug 20, 2026

Sources and claim methodology

Upstream source 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.

Quoted source text, attributed separately from HOL analysis.