What’s Vulnerable › Vulnerabilities

CVE-2026-55780: NanaZip: Uncaught exception / unbounded allocation in NanaZip .NET single-file Extract() via unvalidated entry Size

• Severity: low (CVSS 2.4 v4.0)
• Exploited in the wild: not listed in CISA KEV
• EPSS: 0.6% probability of exploitation in the next 30 days
• Public exploit or detection template: yes
• Published: 2026-07-10 · updated 2026-10-25
• Weakness: CWE-248

Description

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

References

• https://github.com/M2Team/NanaZip/commit/ad62e3b4970b9f01e924c99094d6fed7a42f849a
• https://github.com/M2Team/NanaZip/releases/tag/6.5.1749.0
• https://github.com/M2Team/NanaZip/security/advisories/GHSA-ppm9-5267-rq72
• https://github.com/M2Team/NanaZip/security/advisories/GHSA-ppm9-5267-rq72

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