CVE-2026-55780
LowCVSS 2.4Exploitation Probability (EPSS)
Low risk2th percentile - higher than 2% of all known CVEs
Summary
A vulnerability in NanaZip (a 7-Zip fork for Windows) prior to version 6.5.1749.0 allows process crashes via a crafted .NET single-file bundle. The issue stems from missing validation of the extraction buffer size against the actual file size, potentially leading to std::bad_alloc or std::length_error exceptions.
Risk Assessment
An attacker can crash the NanaZip application, causing denial of service (DoS) and potentially destabilizing the user environment.
Recommendation
Immediately update NanaZip to version 6.5.1749.0 or later, which includes the fix for buffer size validation.
Original NVD description (English source)
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.