Is CVE-2026-42443 exploited in the wild?

No. Junglewise Threat Intelligence has no report of CVE-2026-42443 being exploited in the wild.

How severe is CVE-2026-42443?

Low severity, with a CVSS score of 3.3, published 12 May 2026.

Which products and versions are affected?

M2Team NanaZip 5.0.1252.0 to before 6.0.1698.0.

Is there a fix for CVE-2026-42443?

No fixed version is recorded yet. Check the vendor's advisory in the references below. If you run it, Junglewise drafts a mitigation that fits your setup and applies it once you approve, with senior security engineers behind it.

How is CVE-2026-42443 attacked?

It is attacked with local access, in a network appliance.

Am I affected by CVE-2026-42443?

Check whether you run M2Team NanaZip at an affected version. Junglewise does that check for you around the clock: connect your code, cloud and domains, and it matches new vulnerabilities like this one against what you actually run and tells you when one reaches you.

CVE-2026-42443: M2Team NanaZip integer divide-by-zero in UFS filesystem parser

CVE-2026-42443 · Severity: low · CVSS 3.3 · Published 2026-05-12

NanaZip is an open-source file archiver used to compress and decompress various file formats. A vulnerability in how it handles specific filesystem images (UFS/UFS2) allows an attacker to crash the application by providing a specially crafted file. While this does not lead to data theft or unauthorized access, it results in a denial-of-service where the software stops responding or closes unexpectedly when the malicious file is opened.

Technologies: M2Team NanaZip. Vendors: M2Team.

Quick answers

Is CVE-2026-42443 exploited in the wild?: No. Junglewise Threat Intelligence has no report of CVE-2026-42443 being exploited in the wild.
How severe is CVE-2026-42443?: Low severity, with a CVSS score of 3.3, published 12 May 2026.
Which products and versions are affected?: M2Team NanaZip 5.0.1252.0 to before 6.0.1698.0.
Is there a fix for CVE-2026-42443?: No fixed version is recorded yet. Check the vendor's advisory in the references below. If you run it, Junglewise drafts a mitigation that fits your setup and applies it once you approve, with senior security engineers behind it.
How is CVE-2026-42443 attacked?: It is attacked with local access, in a network appliance.
Am I affected by CVE-2026-42443?: Check whether you run M2Team NanaZip at an affected version. Junglewise does that check for you around the clock: connect your code, cloud and domains, and it matches new vulnerabilities like this one against what you actually run and tells you when one reaches you.

Technical details

An integer divide-by-zero vulnerability exists in the UFS/UFS2 filesystem image parser within NanaZip. The flaw is located in the GetInodeOffset function in NanaZip.Codecs.Archive.Ufs.cpp, where the superblock field 'fs_ipg' (inodes per cylinder group) is read from the disk and used as a divisor without validation. If an attacker provides a crafted UFS image with 'fs_ipg' set to zero, the application triggers a hardware divide-by-zero exception (x86 #DE), leading to an immediate process crash. This occurs during the archive opening phase (IInArchive::Open) before user interaction beyond selecting the file. The issue is fixed in version 6.0.1698.0.

Affected products

M2Team NanaZip 5.0.1252.0 to before 6.0.1698.0

Timeline

2026-04-27: advisory: GitHub Security Advisory published by M2Team
2026-05-12: disclosed: CVE-2026-42443 published to NVD

References

https://github.com/M2Team/NanaZip/security/advisories/GHSA-3x2h-gqqw-g3gm

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