CVE-2026-55780: m2team Nanazip

Low severity, CVSS 2.4. EPSS: 0.4% chance of exploitation in the next 30 days.

NanaZip is the 7-Zip derivative intended for the modern Windows experience. Prior to 6.5.1749.0, NanaZip's .NET single-file bundle handler in NanaZip.Codecs.Archive.DotNetSingleFile.cpp sizes its extraction buffer from the bundle entry Size field, which is only checked for sign and is not validated against the real file size. A crafted bundle can cause an attacker-chosen allocation inside Extract, where std::bad_alloc or std::length_error can escape across the COM STDMETHODCALLTYPE boundary and crash the process. This issue is fixed in version 6.5.1749.0.

Affected products

• m2team Nanazip: before 6.5.1749.0 (fixed in 6.5.1749.0)

Published 2026-07-10. Last modified 2026-07-13.