CVE-2026-55781

NanaZip is the 7-Zip derivative intended for the modern Windows experience. Prior to 6.5.1749.0, NanaZip's UFS and FFS image handler in NanaZip.Codecs.Archive.Ufs.cpp validates the superblock block size only against the MINBSIZE lower bound and does not validate the fs_fsize fragment size, allowing attacker-controlled 32-bit fields to flow into indirect-block, directory, and extraction buffer allocations. A tiny crafted UFS image can force multi-gigabyte allocations during open or extraction, causing memory exhaustion or process termination. This issue is fixed in version 6.5.1749.0.

CVSS

No CVSS.

References

Link	Resource
https://github.com/M2Team/NanaZip/commit/6415b6bff70bc9c486b49cbbc1982724c67f8338
https://github.com/M2Team/NanaZip/releases/tag/6.5.1749.0
https://github.com/M2Team/NanaZip/security/advisories/GHSA-m34h-jf84-m74h

Configurations

No configuration.

History

10 Jul 2026, 17:16

Type	Values Removed	Values Added
New CVE

Information

Published : 2026-07-10 17:16

Updated : 2026-07-10 21:16

NVD link : CVE-2026-55781

Mitre link : CVE-2026-55781

CVE.ORG link : CVE-2026-55781

JSON object : View

Products Affected

No product.

CWE

CWE-400

Uncontrolled Resource Consumption

CWE-789

Memory Allocation with Excessive Size Value

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