Is CVE-2026-44215 exploited in the wild?

No. Junglewise Threat Intelligence has no report of CVE-2026-44215 being exploited in the wild.

How severe is CVE-2026-44215?

Medium severity, with a CVSS score of 4.4, published 12 May 2026.

Which products and versions are affected?

M2Team NanaZip 5.0.1252.0 to 6.0.1698.0.

Is there a fix for CVE-2026-44215?

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-2026-44215 attacked?

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

Am I affected by CVE-2026-44215?

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-2026-44215: M2Team NanaZip heap out-of-bounds write in UFS parser

CVE-2026-44215 · Severity: medium · CVSS 4.4 · Published 2026-05-12

NanaZip is an open-source file archiver used to compress and extract various file formats. A security flaw in how it handles UFS filesystem images allows a specially crafted file to corrupt the application's memory when opened. This could lead to the program crashing or potentially allow more sophisticated attacks, though it requires a user to manually open the malicious file.

Technologies: M2Team NanaZip. Vendors: M2Team.

Quick answers

Is CVE-2026-44215 exploited in the wild?: No. Junglewise Threat Intelligence has no report of CVE-2026-44215 being exploited in the wild.
How severe is CVE-2026-44215?: Medium severity, with a CVSS score of 4.4, published 12 May 2026.
Which products and versions are affected?: M2Team NanaZip 5.0.1252.0 to 6.0.1698.0.
Is there a fix for CVE-2026-44215?: 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-2026-44215 attacked?: It is attacked with local access, in a network appliance.
Am I affected by CVE-2026-44215?: 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

A one-byte heap out-of-bounds null write exists in the UFS/UFS2 filesystem image parser within NanaZip's GetAllPaths function. The vulnerability is caused by a failure to verify that the name length (d_namlen) plus a null terminator fits within the directory record length (d_reclen) or the allocated buffer. An attacker can trigger this by providing a crafted UFS image where a directory entry is placed at the end of a block with a maximum name length value. This allows a null byte to be written up to 254 bytes past the heap allocation boundary. While modern Windows mitigations (CFG, CET) make exploitation difficult, the flaw can cause a denial of service or be used as a primitive for further heap corruption. The issue is fixed in version 6.0.1698.0.

Affected products

M2Team NanaZip 5.0.1252.0 to 6.0.1698.0

Timeline

2026-04-27: advisory: GitHub Security Advisory published by MouriNaruto
2026-05-12: disclosed: CVE-2026-44215 published

References

https://github.com/M2Team/NanaZip/security/advisories/GHSA-44wh-7gc3-w936

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