PT-2026-57236 · M2Team · Nanazip

Published 2026-07-10 · Updated 2026-07-10 · CVE-2026-55781

Mitre

CVSS v4.0

2.4

Low

Base vector

AV:L/AC:L/AT:N/PR:L/UI:P/VC:N/VI:N/VA:L/SC:N/SI:N/SA:N

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.

Fix

Resource Exhaustion

Weakness Enumeration

CWE-789

CWE-400

Related Identifiers

CVE-2026-55781

Affected Products

Nanazip

References · 4

• https://nvd.nist.gov/vuln/detail/CVE-2026-55781 · Security Note
• https://github.com/M2Team/NanaZip/releases/tag/6.5.1749.0 · Note
• https://github.com/M2Team/NanaZip/commit/6415b6bff70bc9c486b49cbbc1982724c67f8338 · Note
• https://github.com/M2Team/NanaZip/security/advisories/GHSA-m34h-jf84-m74h · Note