# CVE-2026-42442: M2Team NanaZip null pointer dereference in UFS parser

Source: https://junglewise.ai/threats/cve-2026-42442-m2team-nanazip-null-pointer-dereference-in-ufs-parser  
Publisher: Junglewise Threat Intelligence, https://junglewise.ai/threats  
Published: 2026-05-12. Updated: 2026-05-18  
License: CC BY 4.0 with a link back

CVE-2026-42442 · 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 flaw in how it handles certain filesystem image files (UFS/UFS2) allows a specially crafted file to crash the application. While this does not lead to data theft or unauthorized access, it can disrupt operations by causing the software to stop responding when a user attempts to open a malicious archive.

Technologies: [M2Team NanaZip](https://junglewise.ai/threats/technologies/nanazip). Vendors: [M2Team](https://junglewise.ai/threats/vendors/m2team).

## Quick answers

**Is CVE-2026-42442 exploited in the wild?** No. Junglewise Threat Intelligence has no report of CVE-2026-42442 being exploited in the wild.

**How severe is CVE-2026-42442?** 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-2026-42442?** 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-2026-42442 attacked?** It is attacked with local access, in a network appliance.

**Am I affected by CVE-2026-42442?** 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 null-pointer dereference exists in the UFS/UFS2 filesystem image parser within NanaZip. The vulnerability occurs because the `Open` function in `NanaZip.Codecs.Archive.Ufs.cpp` fails to verify that the root inode (inode 2) is a directory (`IFDIR`) before calling `GetAllPaths`. If a crafted image sets the root inode to a symbolic link (`IFLNK`) with a small size, the parser takes an embedded-symlink fast path that returns without populating block offsets. This results in a zero-length buffer allocation; subsequent attempts to read directory entries from this null buffer trigger a crash. 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: Original GitHub security advisory published
- 2026-05-12: disclosed: CVE published to NVD

## References

- [https://github.com/M2Team/NanaZip/security/advisories/GHSA-8r4x-fx3w-ph77](https://github.com/M2Team/NanaZip/security/advisories/GHSA-8r4x-fx3w-ph77)

## Related threats

- [NanaZip SquashfsHandler heap out-of-bounds read and information disclosure](https://junglewise.ai/threats/cve-2026-54616-nanazip-squashfshandler-heap-out-of-bounds-read-and-information)
- [M2Team NanaZip NULL pointer dereference in NanaZip.Codecs archive handlers](https://junglewise.ai/threats/cve-2026-55783-m2team-nanazip-null-pointer-dereference-in-nanazip-codecs-archive)
- [M2Team NanaZip uncontrolled memory allocation in WebAssembly handler](https://junglewise.ai/threats/cve-2026-55782-m2team-nanazip-uncontrolled-memory-allocation-in-webassembly)
- [M2Team NanaZip memory exhaustion in UFS and FFS image handler](https://junglewise.ai/threats/cve-2026-55781-m2team-nanazip-memory-exhaustion-in-ufs-and-ffs-image-handler)
- [M2Team NanaZip uncaught exception in .NET single-file handler](https://junglewise.ai/threats/cve-2026-55780-m2team-nanazip-uncaught-exception-in-net-single-file-handler)